The Flash season 1

The Flash
Season 1
Promotional poster
Showrunner	Alex Brow
Starring	Dylan O'Brien Tati Gabrielle Victoria Pedretti Xolo Maridueña Kaitlyn Dever Rahul Kohli Caleb McLaughlin Gugu Mbatha-Raw Dan Stevens Sterling K. Brown Jon Hamm
No. of episodes	15
Release
Original network	Max
Original release	October 1, 2027 (2027-10-01) – January 7, 2028 (2028-01-07)
Season chronology

The first season of the American superhero television series The Flash, based primarily on the Barry Allen incarnation of the Flash from DC Comics, was developed for television by Alex Brow. It was produced by Warner Bros. Television and DC Studios in association with Mercury Pictures and Ellison House Productions, with Brow serving as showrunner.

The season follows Barry as he learns to control his abilities and gradually becomes the masked hero known as the Flash while continuing to investigate the murder of his mother, Nora Allen, which he witnessed as a child. Barry discovers that her killer is another speedster, Eobard Thawne / Reverse-Flash, a mysterious figure from centuries in the future who possesses extensive knowledge of Barry's life and deliberately manipulates his development. While protecting Central City from metahumans and criminals including Leonard Snart, Mick Rory, Sam Scudder, Mark Mardon, James Jesse, Grodd and other members of the Rogues, Barry increasingly realizes that many of his encounters have either been anticipated or directly engineered by Thawne to force him to become faster.

The season premiered on Max on October 1, 2027, and concluded on January 7, 2028, consisting of 15 episodes released weekly. It received positive reviews, with praise directed toward O'Brien's performance, the season-long development of Reverse-Flash, its increasing emphasis on time travel and character relationships, and the progression of Barry from an inexperienced speedster into a more confident hero, though some critics considered its expanding supporting cast overcrowded. A second season was ordered in December 2027.

Episodes

Season one episodes

No. overall	No. in season	Title	Directed by	Written by	Original air date
1	1	"Pilot"	Alex Brow	Alex Brow	October 1, 2027 (2027-10-01)
Twenty years after witnessing his mother Nora's murder by a mysterious speedster, forensic scientist Barry Allen investigates a series of deaths connected to Mercury Labs. While attending the launch of the facility's particle engine with reporter Iris West, Barry is struck by lightning during an explosion and awakens months later with superhuman speed. With assistance from Mercury scientists Harrison Wells, Tina McGee and Cisco Ramon, Barry begins testing his abilities while continuing his investigation. He discovers that Ted Sears, a former Mercury employee injured in an earlier accident, is responsible for the killings and is targeting those he blames for his condition. Barry attempts to stop Sears but is initially defeated. During their second confrontation, Barry rescues several workers endangered by Sears before ultimately defeating him and preventing further casualties. Afterwards, Barry decides to continue using his powers to protect Central City. Elsewhere, the mysterious speedster from Barry's childhood is revealed as the Reverse-Flash, who has secretly been monitoring Barry for years.
2	2	"A Flash of Red"	Jennifer Phang	Maya Ellison & Christina Hodson	October 8, 2027 (2027-10-08)
Barry continues using his powers to protect Central City, attracting the attention of criminal Leonard Snart, who steals cryogenic technology and develops a weapon capable of slowing him. Snart uses a robbery to test the weapon against Barry and escapes after injuring him. Barry later discovers that Snart and his associates are planning to rob a federal currency transfer aboard the Green Line. He confronts them on the train, but Snart escapes after forcing Barry to choose between pursuing him and saving the passengers when the train is sent toward an unfinished section of track. Barry manages to stop the passenger car before it reaches the gap. Following the rescue, Iris publishes an article referring to the mysterious speedster as "The Flash", a name Barry subsequently adopts. Snart begins modifying his weapon after learning from their encounter, while Reverse-Flash continues monitoring Barry from his hidden archive.
3	3	"Afterimage"	Stephen Williams	Jordan Kaye	October 15, 2027 (2027-10-15)
As Central City becomes accustomed to the Flash, former Mercury Labs scientist Danton Black develops the ability to create duplicates of himself and attacks the facility. Barry learns that Danton had been conducting experimental research intended to save his terminally ill sister before Harrison Wells terminated the project. Danton subsequently targets those he holds responsible for her death, but discovers that Wells was responsible for ending his research and abducts him. During Barry's attempt to rescue Wells, Danton learns that Barry is the Flash. Barry identifies the original Danton among his duplicates and subdues him, but an unstable experiment threatens the facility, forcing them to work together to contain it. Danton is taken into custody and tells police that he will not reveal Barry's identity. Meanwhile, Reverse-Flash continues monitoring Barry and becomes concerned by the number of people who know his secret.
4	4	"Thin Air"	Uta Briesewitz	Kieran Fitzgerald	October 22, 2027 (2027-10-22)
Barry investigates the murder of an inmate at Iron Heights and discovers that Kyle Nimbus, a presumed-dead assassin transformed by the particle engine accident, can turn his body into toxic vapor. Nimbus begins targeting those involved in his conviction, and Barry nearly dies after inhaling his vapor while preventing him from killing former prosecutor Evelyn Ross. Seeking a way to counter Nimbus's abilities, Barry reluctantly asks Danton for assistance and discovers a method of forcing Nimbus back into solid form. When Nimbus attacks an assisted-living facility to reach another former target, Barry evacuates the residents and uses a vortex to subdue him, allowing police to take him into custody. Danton is subsequently transferred to a specialized prison unit after continuing to keep Barry's identity secret. However, Reverse-Flash confronts Danton in his cell and kills him to prevent Barry's identity from being exposed.
5	5	"Faster"	Rachel Talalay	Christina Hodson	October 29, 2027 (2027-10-29)
Following Danton's death, Barry discovers security footage showing the yellow-suited speedster responsible and identifies him as the man who killed his mother. Joe accepts Barry's childhood account, while evidence confirms that Danton was murdered using abilities similar to Barry's. The speedster later confronts Barry after stealing experimental technology from Mercury Labs and easily defeats him. Barry and his allies determine that the stolen devices were designed for temporal displacement, leading Barry to suspect that his enemy is from the future and already knows what he will become. After discovering that the speedster has been deliberately provoking him to become faster, the group sets a trap using the remaining technology. Barry performs better during their subsequent confrontation but is again overpowered. The speedster reveals that Nora was not his intended target and that he had originally come for Barry, but refuses to explain his motive until Barry becomes faster. He escapes, while Barry resolves to improve on his own terms. Reverse-Flash is later shown secretly tracking Barry's development.
6	6	"Storm Warning"	Andrij Parekh	Maya Ellison & Sarah Nolen	November 5, 2027 (2027-11-05)
While Barry continues searching for Reverse-Flash, Central City is threatened by Mark Mardon, a presumed-dead criminal who can manipulate the weather. Mardon targets Joe, blaming him for the death of his brother Clyde during a police pursuit eighteen months earlier. After overpowering Barry and recovering Clyde's belongings, Mardon forces Joe to meet him at the freight yard where Clyde died. Their confrontation escalates when Barry intervenes, prompting Mardon to unleash a massive storm over Central City. Barry evacuates civilians before using his speed to disrupt the storm's circulation and weaken Mardon's powers, allowing him to defeat and arrest him. Afterwards, Joe warns Barry against allowing his search for Reverse-Flash to consume his life. During Mardon's transfer to Iron Heights, Leonard Snart and Mick Rory attempt to intercept him, only to discover that Sam Scudder has already freed him. Scudder subsequently recruits Mardon as part of a larger group of criminals forming in Central City.
7	7	"Rogue War, Part 1"	Kari Skogland	Kieran Fitzgerald	November 12, 2027 (2027-11-12)
Barry investigates a conflict between Leonard Snart and his former partner Sam Scudder, who has gained the ability to travel through reflective surfaces and recruits Mark Mardon and Roscoe Dillon. Scudder attacks one of Snart's associates before stealing a photonic prism array capable of expanding his powers, bringing his group into conflict with Snart, Mick Rory and Lisa Snart. Barry becomes caught between the rival groups as Scudder targets Mercury Labs to power the device. Although Barry temporarily prevents him from fully charging it, Scudder escapes and challenges Snart to meet him at an abandoned glassworks. Barry later follows Snart's group there as the two criminal factions confront each other. Scudder connects the prism array to the facility's power supply and uses it to pull Barry into a dimension accessible through mirrors. Snart attempts to free Barry by destroying the mirror connecting him to the real world, but instead seals the exit. Barry becomes trapped in the mirror dimension while Scudder and Snart's groups begin fighting outside.
8	8	"Rogue War, Part 2"	Misha Green	Maya Ellison	November 19, 2027 (2027-11-19)
Barry escapes the mirror dimension and forces the rival Rogues to cooperate with him to shut down Scudder's unstable prism array. After the device is disabled, Reverse-Flash arrives and begins targeting the six Rogues to provoke Barry into becoming faster. He kills Roscoe Dillon, Mark Mardon and Mick Rory before pursuing Sam Scudder into the mirror dimension and killing him as Barry attempts to rescue him. Reverse-Flash later kills Lisa Snart at Mercury Labs, prompting Leonard Snart to join Barry in an attempt to stop him. Barry and Snart use cryogenic technology to temporarily weaken Reverse-Flash, but he escapes the trap and kills Snart. Barry subsequently confronts Reverse-Flash across Central City but is severely injured and defeated. Reverse-Flash refuses to kill Barry, explaining that he needs him to continue becoming faster, before escaping. While Barry recovers, the six Rogues are classified as homicide victims. Reverse-Flash later records Barry's increased speed and prepares for another confrontation connected to Nora Allen's murder.
9	9	"Grodd"	Salli Richardson-Whitfield	Jordan Kaye & Sarah Nolen	November 26, 2027 (2027-11-26)
Still recovering from his injuries, Barry investigates the escape of Grodd, an intelligent telepathic gorilla formerly subjected to military experimentation by General Wade Eiling. After Grodd attacks Central City Zoo, Barry learns that he originated from a Mercury Labs research program before being transferred to Eiling, whose experiments continued after the particle engine explosion gave Grodd enhanced abilities. Grodd later retrieves a neural amplifier and reveals that Reverse-Flash had experimented on him before Barry received his powers. When Eiling attempts to kill Grodd, the amplifier instead increases Grodd's telepathic range, allowing him to control thousands of people at a crowded arena. Barry protects the civilians and disrupts Grodd's control before confronting him in a river tunnel, where he uses an electrical surge to weaken him. Grodd escapes, while evidence of Eiling's experiments leads to his arrest. Barry subsequently begins recovering from his recent defeats. Reverse-Flash later confronts Grodd underground, confirming his involvement in Grodd's past, while Grodd discovers that Reverse-Flash is afraid of Barry.
10	10	"The Man in Yellow"	Hanelle M. Culpepper	Christina Hodson	December 3, 2027 (2027-12-03)
Reverse-Flash attacks Mercury Labs and steals a device capable of detecting temporal displacement, but Barry wounds him during their confrontation and recovers blood and part of his damaged cowl. Analysis confirms that the speedster is a time traveler, while markings on the suit lead Barry to the name "Thawne". Using the cowl's temporal signature, Barry tracks Reverse-Flash to a hidden chamber containing records of Barry's life and a future archive identifying him as Professor Eobard Thawne, a scholar from centuries in the future who studied the Flash. Thawne later confronts Barry at his childhood home, where Barry partially unmasks him before leading him into a trap that suppresses both men's speed. Fully unmasked, Thawne admits to murdering Nora because killing Barry too early would cause him to "lose", but refuses to explain further. Thawne overloads the trap and escapes when Barry chooses to prevent the resulting temporal disturbance from damaging Central City. With Thawne's identity, DNA and confession recorded, Joe reopens Nora's murder case, providing evidence supporting Henry's innocence. Thawne later reviews a timeline showing Barry's life continuing according to his plans.
11	11	"Out of Time"	Justin Benson & Aaron Moorhead	Kieran Fitzgerald & Maya Ellison & Alex Brow & Freddie Goodwin	December 10, 2027 (2027-12-10)
Henry is exonerated and released after new evidence identifies Thawne as Nora's killer. As Henry reunites with Barry and reveals that he witnessed a second, red speedster on the night of Nora's death, Green Arrow and Green Lantern arrive in Central City to investigate temporal disturbances caused by Thawne. Barry learns that Thawne is using a stolen chronal device and Barry's speed to create a pathway through time. Thawne later attacks Mercury Labs and causes a catwalk to collapse toward Wally West; Henry saves Wally but is fatally injured. Grief-stricken, Barry pursues Thawne and inadvertently completes the temporal pathway, following him twenty years into the past. Barry arrives on the night of Nora's murder and realizes that he is the red speedster from his childhood memories. He rescues his younger self but, fearing the consequences of altering history, does not prevent Nora's death. Barry returns to the present and finds the timeline apparently unchanged. Following Henry's funeral, he resumes protecting Central City, while Thawne reveals that Barry's actions have provided him with an unstable route through time.
12	12	"The Trickster"	Deborah Chow	Maya Ellison & Christina Hodson	December 17, 2027 (2027-12-17)
While Barry struggles with Henry's death, James Jesse, a former criminal known as the Trickster, escapes Iron Heights and begins staging elaborate attacks designed to manipulate Barry's speed while stealing technology for a powerful holographic projector. Jesse later reveals Barry's identity to Wally, who learns that Barry is the Flash. After taking dozens of people hostage at an abandoned amusement park, Jesse demands that Wally repair the stolen technology and surrounds the park with explosives triggered by Barry's speed. Barry instead moves cautiously through Jesse's traps while Wally secretly sabotages the projector, allowing Barry to capture Jesse. With the remaining explosives still active, Wally reverses the system and redirects their energy into the projector, saving the hostages. Barry begins allowing himself to reconnect with his friends and family following Henry's death. Meanwhile, Eobard observes Barry and his allies while continuing to stabilize his pathway through time and considers who should become Barry's next loss.
13	13	"Frequency"	Jennifer Phang	Sarah Nolen	December 24, 2027 (2027-12-24)
Reverse-Flash steals a tachyon cell from General Eiling and announces that he intends to return to his own time, beginning a countdown while acquiring additional technology needed to create a temporal corridor. Cisco begins experiencing visions and sensing temporal disturbances before they occur, allowing the group to locate Thawne beneath Old Union Terminal. Meanwhile, Wally struggles with guilt over Henry's death and admits to Wells that he has become indifferent to his own safety. At the terminal, Thawne traps Barry in a repeating memory of Henry's death and attempts to provoke him into running fast enough to complete the corridor. With Cisco and Wally's help, Barry escapes the loop and realizes that Thawne has been manipulating his emotions to increase his speed. Barry stops running and destabilizes the machine, preventing Thawne from returning home, although Thawne escapes with the tachyon cell after partially locking onto the future. Afterwards, Cisco's temporal sensitivity appears to persist, while Thawne briefly opens a portal to his own century before it collapses and identifies Wally as his next means of provoking Barry.
14	14	"The Last Day, Part 1"	Rachel Talalay	Maya Ellison	December 31, 2027 (2027-12-31)
Reverse-Flash begins a 24-hour countdown to his departure and subjects Barry to a series of temporal disturbances designed to measure his abilities and decision-making. Thawne reveals that Wally carries a temporal signature created when Henry saved him and offers to restore Henry if Wally helps him complete his route to the future. Wally refuses and uses a phase-lock device to briefly restrain Thawne, leading Barry and his allies to devise a trap at Mercury Labs. After Barry disables several temporal anchors around Central City, Thawne is captured, but reveals that the trap itself completes the stabilization system he needs and links Wally's temporal signature to the accelerator. Barry is forced to run to prevent Wally from being displaced, allowing Thawne's portal to the year 2466 to open. Barry prevents Thawne from escaping alone, but Thawne drags him through the collapsing portal before it closes. Barry awakens with Thawne inside the future Flash Museum, where Thawne reveals that his hatred of the Flash began there.
15	15	"The Last Day, Part 2"	Alex Brow	Alex Brow	January 7, 2028 (2028-01-07)
Trapped in 2466, Barry learns that Eobard once idolized the Flash and recreated his powers, but became Reverse-Flash after discovering his future crimes in the Flash Museum and blaming Barry for treating him as a murderer before he had committed them. Eobard reveals that his powers are tethered to Barry's through the Speed Force and attempts to convince Barry to alter history, but Barry refuses. Cisco uses Wally's temporal connection to guide Barry back to 2026, where Eobard follows. During the ensuing battle, Cisco separates their speed frequencies, inadvertently freeing Eobard from his dependence on Barry and allowing him to kill Barry without endangering himself. Wally voluntarily uses his temporal signature to tether Eobard again, enabling Barry to open the Speed Force and cast Eobard into it. Central City's temporal disturbances end, while Barry resumes his life as the Flash and begins a romantic relationship with Iris. Wally later displays unexplained speed-related energy, Cisco experiences another vision of an alternate reality, and Eobard awakens alive within a timeless void.

Cast and characters

See also: List of The Flash characters

Main

• Dylan O'Brien as Barry Allen / the Flash
• Tati Gabrielle as Iris West
• Xolo Maridueña as Cisco Ramon
• Rahul Kohli as Harrison Wells
• Caleb McLaughlin as Wally West
• Gugu Mbatha-Raw as Tina McGee
• Dan Stevens as Eobard Thawne / Reverse-Flash
• Sterling K. Brown as Joe West
• Jon Hamm as Henry Allen

Recurring

• Boyd Holbrook as Leonard Snart / Captain Cold
• Winston Duke as Mick Rory / Heat Wave
• Sadie Sink as Lisa Snart
• LaKeith Stanfield as Sam Scudder / Mirror Master
• Yahya Abdul-Mateen II as Mark Mardon / Weather Wizard
• Jesse Plemons as Danton Black / Multiplex
• Lewis Pullman as Roscoe Dillon / the Top
• David Harbour as General Wade Eiling
• Amy Adams as Nora Allen
• Keith David as the voice of Gorilla Grodd

Guest

• Michael Shannon as Ted Sears
• Riz Ahmed as Kyle Nimbus / the Mist
• Bill Skarsgård as James Jesse / the Trickster
• Jensen Ackles as Oliver Queen / Green Arrow
• Glen Powell as Hal Jordan / Green Lantern
• Carrie Coon as Detective Kramer

Production

Development

On January 12, 2024, Mob Studios announced that it had ordered The Flash directly to series, with a 15-episode first season. The series was developed as a new adaptation of the Barry Allen incarnation of the character and was not connected to the previous television series. Alex Brow was announced as showrunner in June 2024, and additionally served as an executive producer and one of the principal writers for the season.

Early development focused on establishing a version of Barry that would begin his career without immediately possessing the full range of abilities traditionally associated with the character. Brow said that the creative team wanted Barry's progression as the Flash to occur across the entire season, with abilities including phasing, advanced perception and more complex uses of his speed introduced gradually. The producers similarly wanted Central City to develop alongside Barry, beginning as a relatively conventional city before the destruction of the Mercury particle engine resulted in the appearance of metahumans and increasingly unusual threats.

The season was designed around Reverse-Flash as its principal antagonist, with the mystery surrounding Nora Allen's murder functioning as the narrative connecting the otherwise distinct threats faced by Barry. Rather than immediately revealing Eobard Thawne's identity and motivations, the writers planned for his involvement to become progressively clearer throughout the season. His early appearances were therefore largely restricted to brief confrontations, surveillance of Barry, and indications that he possessed knowledge of events that had not yet occurred.

Brow described the season as having a gradual escalation in scale. The opening episodes primarily depict Barry learning to operate as a superhero and encountering individual metahumans, while the middle portion introduces the Rogues and brings Barry into direct conflict with Reverse-Flash. The final episodes increasingly focus on time travel, Barry's relationship with Thawne and the consequences of altering established events. The two-part finale, "The Last Day", was developed as the culmination of storylines involving Nora and Henry Allen, Wally West, Cisco Ramon's developing abilities, and Thawne's attempt to return to the 25th century.

Several elements were deliberately established for potential future seasons without being resolved during the first. These included the changes affecting Wally following his exposure to temporal energy, Cisco's ability to perceive vibrational and temporal phenomena, and the nature of the Speed Force. Brow said that the intention was for the finale to conclude Barry's immediate conflict with Thawne while demonstrating that the consequences of their rivalry would continue beyond the season.

Writing

Writing for the first season began in early 2024 following the series order. Brow said that the writers initially concentrated on establishing the chronology of the season and determining how closely its characters would correspond with their comic-book counterparts. In May 2024, he revealed that he was in the middle of planning the season's timeline and said that he wanted to put significant effort into ensuring that the characters were "completely faithful to the comics". An outline for all 15 episodes was completed during development.

Brow prepared two versions of the season's larger story. The first was structured so that the season could function as a largely self-contained story if the series was not renewed, while the second retained additional storylines that could continue into subsequent seasons. Both versions concluded the immediate Reverse-Flash storyline, but the multi-season version included additional developments involving Wally, Cisco and the Speed Force. Elements of the latter version were ultimately incorporated into the completed season.

In July 2024, Brow confirmed that Reverse-Flash would serve as the principal antagonist. He said that the writers wanted to avoid extensively repeating storylines previously adapted in the 2014 series and instead intended to construct a different version of Barry and Thawne's rivalry. One of the major differences was the decision to reveal Thawne's identity before the finale and subsequently explore why he became Reverse-Flash. The writers developed Thawne as someone who originally admired the Flash and recreated his powers before discovering historical records identifying himself as Barry's greatest enemy. This created a causal loop in which Thawne's knowledge of his future contributed to him eventually fulfilling it.

The writers also decided that Thawne would not simply attempt to kill Barry. Because his artificially recreated speed was eventually revealed to be temporally linked to Barry's, Thawne instead spends much of the season forcing Barry to become faster. This concept informed several earlier episodes, in which apparently unrelated attacks or encounters are later revealed to have provided Thawne with information about Barry's abilities, reactions and emotional limits.

Brow confirmed that multiple members of the Rogues would appear throughout the season, saying that they would "cause some hell" for Barry. Rather than introducing them as an established organization, the writers gradually built connections between several criminals. Leonard Snart, Mick Rory, Sam Scudder, Mark Mardon, Roscoe Dillon and Lisa Snart eventually become involved in the two-part "Rogue War" storyline, which was conceived as a conflict between competing groups of criminals rather than a conventional battle between the Flash and a unified Rogues team.

The conclusion of "Rogue War" was designed to significantly change the tone of the season. Reverse-Flash enters the conflict and kills several of the Rogues, demonstrating that characters who had previously represented major threats to Barry were themselves vulnerable to Thawne. The storyline also allowed the writers to move the season away from primarily episodic metahuman stories and into the more heavily serialized second half.

"Gorilla Grodd" was developed as a largely self-contained episode following "Rogue War", while also revealing that Thawne had conducted experiments before Barry became the Flash. The writers used Grodd's history with Mercury Labs and General Wade Eiling to expand the consequences of the particle-engine project beyond the metahumans directly created by its destruction.

The final six episodes were written as a more continuous storyline. "The Man in Yellow" reveals Thawne's identity and establishes his origin in the future, while "Out of Time" sends Barry to the night of Nora's murder and reveals that he was the red speedster who rescued his younger self. Brow said that Barry choosing not to prevent Nora's death was important because the series could not allow time travel to become an uncomplicated method of reversing personal tragedy.

Henry Allen's death later in the episode was similarly intended to prevent Barry's decision from becoming emotionally easy. The writers wanted Barry to demonstrate that he understood the dangers of rewriting history while immediately confronting another loss he desperately wanted to undo. Henry's death also became central to Wally's storyline, with his survivor's guilt developing across the final episodes rather than being resolved immediately.

"The Trickster" was positioned between the season's larger temporal storylines and was intentionally written as a more conventional Flash adventure. However, it also reveals Barry's identity to Wally and further integrates him into the Mercury Labs group. "Frequency" then expands Cisco's developing perception of temporal disturbances and establishes the final mechanics of Thawne's plan.

The two-part finale, "The Last Day", was among the earliest stories outlined for the season. Part one focuses on Thawne manipulating Barry into completing the temporal pathway required to reach the year 2466, while part two reveals his complete origin and introduces the term "Speed Force". The writers avoided having Barry defeat Thawne solely by becoming faster. Instead, the final confrontation depends on Barry refusing to fight according to Thawne's expectations and accepting assistance from his allies. Wally's temporal connection and Cisco's ability to perceive the speedsters' frequencies ultimately allow the group to isolate Thawne before Barry forces him into the Speed Force.

The finale also established several storylines for the second season. Wally briefly generates unexplained golden electricity, Cisco experiences a vision involving blue lightning and another version of reality, and Thawne is shown surviving within an unidentified space outside conventional time.

Casting

In June 2024, reports indicated that Grant Gustin, who portrayed Barry Allen in The CW's The Flash, had been discussed in connection with the project. Brow subsequently denied that Gustin would reprise the role, explaining that the new series was intended to have a separate continuity and interpretation of Barry. He confirmed that another actor had already entered discussions for the part.

Dylan O'Brien was announced as Barry Allen / the Flash in August 2024. Brow said that the producers were looking for an actor capable of playing both Barry's comedic awkwardness and the more emotionally difficult material surrounding Nora's murder and his relationship with Thawne. O'Brien underwent physical preparation before filming and worked with the stunt department to develop a distinct physical style for Barry both at normal speed and during sequences filmed from his accelerated perspective.

Casting for the remaining regular roles took place throughout late 2024 and 2025. Tati Gabrielle was cast for the remaining regular roles took place throughout as Iris West, while Sterling K. Brown and Jon Hamm joined as Joe and Henry Allen, respectively. Xolo Maridueña, Rahul Kohli and Gugu Mbatha-Raw were cast as members of the Mercury Labs group, with Caleb McLaughlin joining as Wally West.

Dan Stevens was cast as Eobard Thawne / Reverse-Flash. The production initially attempted to limit publicity surrounding the extent of his role, with early promotional material emphasizing the Reverse-Flash costume rather than Thawne himself. Brow said that Stevens was cast partly because the character needed to remain threatening after his identity was revealed, as the writers did not want the mystery of the man in the yellow suit to be the only source of interest surrounding the antagonist.

The recurring Rogues were cast separately rather than as a single ensemble. Boyd Holbrook and Winston Duke were cast as Leonard Snart and Mick Rory, with LaKeith Stanfield later joining as Sam Scudder. Yahya Abdul-Mateen II was cast as Mark Mardon, while Jesse Plemons portrayed Danton Black. Sadie Sink and Lewis Pullman were cast as Lisa Snart and Roscoe Dillon, respectively.

Keith David provided the voice of Grodd, while the character's physical performance was created through motion-capture and visual effects. Bill Skarsgård was cast as James Jesse / the Trickster. Jensen Ackles and Glen Powell made guest appearances as Oliver Queen / Green Arrow and Hal Jordan / Green Lantern during the final episodes. Their appearances were kept out of the earliest marketing for the season.

Filming

Principal photography began in Vancouver in April 2026 under the working title Mercury. Vancouver, Burnaby and New Westminster were used extensively to represent Central City, while additional establishing and second-unit photography took place in Chicago. The production constructed standing sets for Mercury Labs, the Central City Police Department, Joe West's house, the Central City Citizen newsroom and several recurring city interiors on soundstages in Burnaby.

The Mercury Labs set was designed around a large central Cortex connected to practical laboratory spaces, a machine shop and portions of the particle-accelerator complex. Unlike the more futuristic equipment used later in the season, the facility initially uses technology intended to appear experimental but physically achievable. Additional sections of the complex were constructed as required for the season's temporal storylines, including the accelerator ring used extensively in "Frequency" and "The Last Day".

Production designer Template:Ill approached Central City as a comparatively bright and active metropolitan environment. Brow wanted the city to appear worth protecting rather than functioning solely as a backdrop for crime. The design therefore emphasized populated streets, public transport, parks and recognizable civic spaces. As the season progresses, damage from metahuman incidents and Thawne's temporal experiments becomes increasingly visible.

The two-part "Rogue War" required extensive use of practical environments representing the evidence annex, Mercury Labs and the abandoned glassworks. Reflective materials were incorporated throughout the latter set so that Scudder's mirror abilities could be achieved through a combination of practical photography, duplicated sets and digital extensions. Portions of the set were reconstructed in reversed layouts for scenes taking place inside the mirror dimension.

O'Brien's speed sequences were filmed using a combination of treadmills, wire rigs, high-speed photography, motion-control cameras and extended practical sets. Rather than representing Barry exclusively as a computer-generated figure surrounded by lightning, the production sought to retain O'Brien's physical performance whenever possible. Tracking vehicles and programmable camera rigs were used to photograph him moving through environments while foreground and background action was recorded at different frame rates.

Separate visual rules were developed for Barry and Thawne. Barry's movement increasingly becomes controlled and efficient throughout the season, while Thawne was filmed with more abrupt changes in direction and deliberately unnatural body positioning. Their later fights required O'Brien and Stevens to rehearse complete sections of choreography at normal speed before individual movements were separated and recombined during post-production.

The Flash Museum and 25th-century Central City seen in "The Last Day, Part 2" were among the season's largest production environments. Portions of the museum, including the central Flash statue and Origin Gallery, were constructed practically, while the surrounding structure and future city were created through digital set extensions. The museum was designed to appear celebratory from Barry's perspective while becoming increasingly oppressive as Thawne explains his history there.

Scenes set during Nora Allen's murder were filmed multiple times during production. The sequence first appears from Barry's childhood perspective before later episodes reveal additional speedsters and events surrounding the murder. To maintain continuity, the production preserved the Allen house set and used the same blocking for Nora, Henry and the younger Barry while progressively adding new elements to the scene.

Filming of the season concluded in February 2027. Additional photography was subsequently completed for several visual-effects sequences in "Out of Time", "Frequency" and both parts of "The Last Day".

Design and costumes

Barry's Flash suit was designed to appear as equipment created for practical use rather than a completed superhero uniform. Earlier versions use visible seams, reinforced sections and separate protective components, with alterations made throughout the season as Cisco improves the design. The lightning emblem and overall silhouette gradually become closer to the character's traditional comic-book appearance.

Reverse-Flash's costume was deliberately designed as a visual inversion of Barry's without simply recoloring the Flash suit. Its surface incorporates darker sections around the joints and torso, while internal lighting was used to produce the character's red eye effect during close-up photography. Damage accumulated by the costume during later episodes was retained between appearances.

The Rogues were generally given grounded costumes built around their equipment rather than traditional superhero-style uniforms. Snart's clothing was designed around the cooling system required by his Cold Gun, while Rory's equipment incorporated heat-resistant materials. Scudder's wardrobe made increasing use of reflective textures as his abilities became more powerful.

Visual effects

Visual effects for the season were produced by Industrial Light & Magic, Wētā FX, Framestore, Rodeo FX and Scanline VFX. The effects work included Barry and Thawne's speed, Scudder's mirror dimension, Grodd, Mardon's weather manipulation, temporal distortions throughout Central City, the 25th-century setting and the Speed Force.

Barry's speed was represented through displaced air, pressure distortion, brief red electrical discharges and environmental reactions rather than a continuous lightning trail. Objects near Barry vibrate, deform or move in response to the pressure created by his movement. Sequences shown from Barry's perspective frequently depict the surrounding environment in extreme slow motion while allowing Barry to move at apparently normal speed.

Reverse-Flash's effects were deliberately less stable. His lightning incorporates yellow and red elements, while surrounding debris occasionally appears to move in reverse or toward him. The effect becomes increasingly distorted during the final episodes as the series reveals that his artificially created speed is temporally unstable.

The mirror dimension introduced in "Rogue War, Part 1" was constructed using digitally repeated reflections of physical locations around Central City. Rather than depicting the environment as a completely separate world, Barry remains able to observe portions of reality through reflective surfaces while being unable to physically reach them.

Grodd was created through performance capture combined with digital animation. The effects team sought to retain realistic gorilla anatomy while making subtle alterations to his facial movement to accommodate speech and telepathy. His psychic communication is primarily represented through sound design and changes in the surrounding environment rather than visible energy.

Temporal effects became increasingly prominent during the final five episodes. Different periods of Central City were composited into the same frame, allowing buildings, vehicles and people from different eras to briefly occupy the same physical locations. The production created separate visual signatures for ordinary time travel, temporal echoes and the Speed Force so that the effects could remain distinguishable during the finale.

The Speed Force itself was intentionally left visually abstract. Rather than depicting it as a conventional location, the finale represents it as an apparently infinite environment of white-gold energy, fragmented memories and overlapping moments in time. The production team wanted its first appearance to establish that Barry had interacted with something considerably larger than the temporal technology used by Thawne without fully explaining its nature.

Music

Natalie Holt composed the score for the season. Barry's primary theme combines rapidly repeating strings, electronic percussion and an ascending brass progression. Holt said that the theme was written to feel incomplete during the opening episodes, with additional instrumentation introduced as Barry becomes more confident as the Flash.

Reverse-Flash's theme uses reversed recordings, distorted breathing and electronic tones played beneath a recurring low brass figure. Portions of Barry's theme were incorporated into Thawne's music after the writers revealed that he originally recreated his powers in an attempt to become like the Flash. The two motifs increasingly overlap during their confrontations before separating during the finale.

The Rogues were given related musical elements rather than completely independent themes. Snart's music introduced a recurring rhythmic phrase that was subsequently altered for Rory, Scudder and the other Rogues. The motifs were combined during "Rogue War" before being disrupted by the introduction of Thawne's theme.

The score for "Out of Time" incorporates altered versions of music previously used during scenes involving Nora Allen, while "The Last Day, Part 2" reprises themes from across the season during Barry and Thawne's journey through time. Holt composed a separate musical identity for the Speed Force using layered vocals, processed strings and sustained electronic tones.

The season's soundtrack was released digitally in two volumes, with the second focusing primarily on music from "Rogue War" through "The Last Day". An extended suite containing music from Barry and Thawne's final confrontation was included on the second release.

Marketing

Marketing for the first season was designed around Barry Allen's emergence as the Flash and the mystery of the yellow speedster responsible for Nora Allen's murder, with Warner Bros. and Mob Studios avoiding significant details concerning Eobard Thawne's identity and the season's later time-travel storyline.

The first promotional material was released in October 2026, shortly after principal photography had begun. A short production teaser featured close-up footage of Barry's partially completed suit, the Mercury Labs particle engine and red lightning moving through Central City, ending with a brief image of a yellow figure standing inside the Allen family home. The footage did not show the Reverse-Flash's face or identify the character by name. A first-look image of Dylan O'Brien in costume was released the following day.

An initial teaser trailer was released in February 2027. It focused on Barry's life as a forensic scientist, the destruction of the Mercury particle engine and his discovery of his powers. The trailer also introduced Iris West, Joe West, Cisco Ramon, Tina McGee and Harrison Wells, and included brief footage of Leonard Snart and several unidentified metahumans. Reverse-Flash appeared only in several single-frame shots accompanied by the phrase "Run, Barry". The marketing campaign deliberately avoided footage from the season's later episodes, particularly material involving time travel, Henry Allen's release from prison and the Flash Museum.

The series had a major promotional presence at San Diego Comic-Con in July 2027. O'Brien, Tati Gabrielle, Xolo Maridueña, Sterling K. Brown, Caleb McLaughlin, Rahul Kohli, Gugu Mbatha-Raw and showrunner Alex Brow appeared during the series' panel, where footage from the first four episodes was shown. A new poster depicted Barry running through Central City while yellow lightning followed behind him, accompanied by the tagline "You can't outrun your past."

The first full trailer was released online following the Comic-Con presentation. It emphasized Barry's transformation into the Flash, the appearance of metahumans following the Mercury Labs accident and his investigation into Nora's death. Footage included Captain Cold's first confrontation with Barry, Mark Mardon's weather manipulation, Grodd, the Trickster and several members of the Rogues. The trailer ended with Barry confronting Reverse-Flash outside his childhood home. The speedster's face and identity remained concealed.

Character posters for Barry, Iris, Joe, Cisco, Wally, Wells and Tina were released throughout August 2027. Separate villain posters were subsequently released for Captain Cold, Heat Wave, Mirror Master and Weather Wizard. Reverse-Flash received a poster showing only his silhouette surrounded by yellow and red lightning. Unlike the other characters, no actor was credited on the poster.

A final trailer was released in September 2027, approximately three weeks before the premiere. It placed greater emphasis on the season's serialized storyline and Barry's growing obsession with discovering the identity of the man in yellow. The trailer included previously unseen footage of the Rogues fighting one another, Grodd attacking Central City, Barry running alongside Reverse-Flash and Henry Allen in prison. Its final sequence showed Barry asking how his enemy knew his name before cutting to the title card and the season's October 1 premiere date.

Warner Bros. organized promotional installations in several major cities during the week preceding the premiere. The installations recreated sections of the Mercury Labs particle engine and used synchronized lighting to produce simulated red and yellow lightning effects. Promotional partnerships also included digital advertisements appearing to distort or briefly reverse online video before revealing the series' logo.

Following the release of "Faster", marketing increasingly acknowledged Reverse-Flash as the season's central antagonist. Promotional material for the two-part "Rogue War" storyline focused primarily on the escalating conflict between Central City's criminals and did not reveal Reverse-Flash's involvement in the second part. After the episode was released, a poster featuring the Flash and Reverse-Flash facing one another was published with the tagline "He was never trying to kill him."

The campaign for "The Man in Yellow" avoided revealing Eobard Thawne's identity. Trailers instead promoted the episode around Barry finally discovering who was beneath the Reverse-Flash mask. Following its release, Warner Bros. released an unmasked character poster featuring Dan Stevens as Thawne and a short featurette examining the development of the character's costume, powers and relationship with Barry.

Promotion for the final episodes was centered on the phrase "The Last Day", which initially appeared without explanation on social media accounts associated with the series. A series of countdown images was subsequently released, each depicting a different character alongside a decreasing digital clock similar to the one used by Thawne in "The Last Day, Part 1".

The official trailer for the two-part finale was released after "Frequency". It showed temporal disturbances spreading across Central City, Barry and Reverse-Flash fighting inside the Mercury Labs accelerator, and brief images of Central City in different time periods. Footage of the 25th century and the Flash Museum was omitted. The trailer ended with Thawne telling Barry that it was his "last day here".

A separate poster for "The Last Day, Part 2" depicted red and yellow lightning entering a white fracture in space, accompanied by the tagline "Every race has an ending." Details concerning Thawne's origin, the Speed Force and Barry's journey to 2466 were withheld until the episode's release.

Release

Streaming

The first season premiered in the United States on Max on October 1, 2027. The season consists of 15 episodes, which were released weekly on Fridays, with the season finale, "The Last Day, Part 2", released on January 7, 2028.

The premiere was also broadcast on HBO on October 1 as a promotional simulcast before becoming available on Max. Subsequent episodes premiered exclusively on Max in the United States. Warner Bros. Discovery promoted the weekly release model as a means of allowing the season's mysteries, particularly the identity and motivations of Reverse-Flash, to develop between episodes rather than releasing the season simultaneously.

Episodes were released on Max in international territories where the service was operating at the time. In regions without Max, distribution was handled through Warner Bros. Discovery's existing streaming and television partners, with release schedules varying by territory.

The two "Rogue War" episodes were promoted as the season's first two-part event and were released on consecutive weeks. Similar event branding was used for the season finale, "The Last Day, Part 1" and "The Last Day, Part 2".

Theatrical screenings

Warner Bros. held advance theatrical screenings of the pilot in selected cities in September 2027 as part of the season's promotional campaign. The screenings were followed by recorded question-and-answer sessions featuring members of the cast and production team.

The final two episodes received limited theatrical event screenings in selected theaters in the United States, Canada, the United Kingdom and Australia on January 7, 2028. "The Last Day, Part 1" and "The Last Day, Part 2" were presented consecutively as a feature-length season finale, with the screenings beginning several hours after the second episode became available on Max in order to avoid providing theatrical audiences with earlier access to the conclusion.

The theatrical presentation included an introductory featurette about the production of the finale and the creation of the 25th-century Central City and Flash Museum sequences. No additional narrative material was included in the theatrical version.

Home media

The complete first season was released on Ultra HD Blu-ray, Blu-ray and DVD on May 14, 2028. The physical release included all 15 episodes, deleted scenes, selected episode commentaries and several behind-the-scenes featurettes covering the development of Barry's speed effects, the Rogues, Grodd, Reverse-Flash and the production of the two-part finale.

Additional features included O'Brien's original Flash costume screen test, concept art for Central City and the Flash Museum, stunt rehearsals for several Flash and Reverse-Flash confrontations, and a featurette examining the reconstruction of the Allen family home for the season's various depictions of Nora Allen's murder.

The release also included an extended making-of documentary titled The Man in Yellow: Building the Reverse-Flash, which covered the development of Eobard Thawne's season-long storyline, Stevens's performance, the visual distinction between Barry and Thawne's speed, and the production of their final confrontation.

A digital purchase edition of the season was made available following the conclusion of its Max release. Individual episodes had previously become available through participating digital retailers after their original streaming premieres.

Reception

Critical response

The first season received generally positive reviews, with critics praising Dylan O'Brien's performance as Barry Allen, the season-long development of Reverse-Flash, the relationship between Barry and Joe West, and the gradual transition from episodic metahuman stories into a serialized time-travel narrative. The Rogues storyline, Barry and Eobard Thawne's rivalry, and the final four episodes received particular acclaim. Criticism was directed toward the season's large supporting cast, the amount of scientific exposition in several episodes, and the pacing of some of the earlier standalone stories.

The review aggregator Rotten Tomatoes reported an approval rating of 91% based on 42 reviews, with an average rating of 8.1/10. The website's critical consensus stated that the season combined "energetic superhero spectacle with an unexpectedly personal battle over grief, destiny and the choices that create a hero". Metacritic, which uses a weighted average, assigned the season a score of 78 out of 100 based on 18 critics, indicating "generally favorable reviews".

The pilot received positive reviews. Nathan Cole of Screen Current gave the episode four out of five stars and praised its decision to make Nora Allen's murder "the emotional engine of the series rather than convenient superhero backstory". Cole particularly praised Barry's relationship with Joe and the final reveal of Reverse-Flash observing Barry from an archive containing information about his future. He was more critical of the episode's length, arguing that the Mercury Labs accident, supporting cast and multiple mysteries occasionally made it feel overstuffed. Mara Ellison of The Television Ledger praised the crime-procedural elements and Barry's background as a forensic scientist, writing that they gave him "a reason to solve problems rather than simply outrun them".

"A Flash of Red" was praised for developing Barry's limitations and introducing Leonard Snart as an opponent capable of exploiting them. Julian Mercer of Frame & Panel graded the episode a B+, describing Snart as "the first villain who understands that beating the Flash does not require being faster than him". Critics also responded positively to Barry accepting the name "the Flash" following Iris's coverage of his rescue of the Green Line passengers.

"Afterimage" received strong reviews, particularly for its portrayal of Danton Black. Elise Ward of Television Review Quarterly awarded it four-and-a-half stars out of five and praised the decision to portray Danton as a grieving scientist rather than a conventional supervillain. Ward also praised Barry defeating him by identifying the original among his duplicates rather than simply overpowering them.

"Thin Air" received positive-to-mixed reviews. Critics praised Kyle Nimbus's vapor abilities and the episode's darker prison storyline, while some considered its structure more conventional than the preceding episode. The final scene in which Reverse-Flash murders Danton after discovering that he knows Barry's identity received particular acclaim. Naomi Keller of Serial Screen described it as "brutal, quiet and considerably more frightening than another citywide battle would have been".

"Faster" received widespread acclaim and was frequently described as the season's strongest episode to that point. Rowan Hale of Screen Current awarded it nine out of ten and praised the decision to bring Barry and Reverse-Flash into direct conflict earlier than expected. Hale characterized their confrontation as "less a superhero fight than an abusive lesson", noting that Thawne appears more interested in improving Barry than defeating him. Joe admitting that he now believed Barry's childhood account of Nora's murder was also widely praised.

"Storm Warning" received positive reviews, particularly for its focus on Joe and his history with Mark and Clyde Mardon. Theo Grant of The Episodic gave the episode four out of five stars and called Joe and Mardon's confrontation at the freight yard "one of the season's best scenes without Barry throwing a single punch". Barry disrupting Mardon's citywide storm was praised for expanding the scale of his abilities while retaining physical consequences.

"Rogue War, Part 1" received strong reviews for bringing together several previously established antagonists. Rebecca Shaw of Frame & Panel awarded the episode an A− and praised the decision to give the Rogues "relationships, grudges and loyalties that exist independently of the Flash". The cliffhanger in which Scudder traps Barry inside the mirror dimension was particularly well received.

"Rogue War, Part 2" received widespread acclaim. Amanda Keene of Serial Screen awarded it nine-and-a-half out of ten, praising Barry's escape from the mirror dimension, the temporary cooperation between the rival Rogues and the abrupt arrival of Reverse-Flash. The sequential deaths of Roscoe Dillon, Mark Mardon, Mick Rory, Sam Scudder, Lisa Snart and Leonard Snart were regarded as a major tonal shift for the season. Leonard's final warning to Barry not to allow Thawne to define him received particular praise, although some critics questioned the decision to kill most of the established Rogues in a single episode.

"Grodd" received positive reviews, with critics praising its decision to connect Grodd's origin to both Mercury Labs and Thawne's activities before Barry became the Flash. Daniel Reeves of The Episodic praised Keith David's vocal performance and called Grodd "an actual character rather than a visual-effects challenge with dialogue". Barry breaking free from Grodd's psychic recreation of Nora's death and subsequently choosing not to pursue the injured Grodd were also praised. Some reviewers considered General Eiling's storyline less developed, though his arrest was generally viewed as an effective conclusion to the episode.

"The Man in Yellow" received widespread acclaim for formally revealing Reverse-Flash as Eobard Thawne. Leah Price of The Television Ledger praised Dan Stevens' performance after the character's unmasking and wrote that revealing Thawne's identity before the finale "turns the mystery from who he is into the much more interesting question of why Barry matters to him". Critics also praised the episode for connecting Thawne's equipment to future technology and for using the reopening of Nora's murder investigation to begin clearing Henry Allen's name.

"Out of Time" received widespread acclaim and was frequently cited as one of the season's strongest episodes. Critics praised Henry's exoneration, the appearances of Green Arrow and Green Lantern, and the revelation that Barry was the red speedster who rescued his younger self on the night of Nora's murder. Marcus Venn of The Television Ledger described Barry's decision not to prevent Nora's death as "the moment the series stops treating time travel like a fantasy and starts treating it like responsibility".

Henry's death while saving Wally was particularly praised for occurring immediately after his exoneration. Rebecca Shaw of Frame & Panel called the sequence "almost offensively cruel, but dramatically precise", arguing that Barry choosing not to rewrite Nora's death would have carried less weight if he was not immediately confronted with another tragedy he could potentially attempt to reverse.

"The Trickster" received positive reviews and was described as a deliberate reduction in scale following "Out of Time". Bill Skarsgård's performance as James Jesse received praise, with Nathan Cole describing him as "a villain who understands that making Barry stop is considerably more interesting than trying to outrun him". Wally learning Barry's identity and helping disable Jesse's plan were also praised, although some critics considered the placement of a comparatively standalone episode so close to the finale unusual.

"Frequency" received strong reviews for accelerating the season's final storyline and expanding Cisco's role. Critics praised the development of Cisco's ability to perceive temporal disturbances before they occurred and his growing importance in predicting Thawne's movements. Elise Ward of Television Review Quarterly called Cisco's emerging abilities "one of the season's most successful pieces of long-form setup because the show allows him to become frightened by them before making them useful".

The episode's repeated recreation of Henry's death divided reviewers. Some considered Thawne's use of the memory emotionally effective, while others felt the sequence risked overusing the event shortly after it occurred. Barry ultimately refusing to continue powering Thawne's temporal corridor was nevertheless praised as evidence of his growing ability to recognize Thawne's manipulation.

"The Last Day, Part 1" received widespread acclaim. Critics praised the 24-hour countdown structure, Thawne's temporal attacks across Central City and the increased prominence of Wally. Amanda Keene awarded the episode nine out of ten, writing that its strongest decision was allowing Wally to reject Thawne's offer to restore Henry without Barry making the decision for him.

The reveal that the team's attempt to imprison Thawne had instead completed his temporal stabilizer was also praised. Critics highlighted the sequence in which Barry is forced to run inside the Mercury accelerator to prevent Wally from becoming temporally displaced, inadvertently opening Thawne's route to the future. The cliffhanger, in which Thawne drags Barry through the closing portal and Barry awakens inside the Flash Museum in 2466, was widely praised.

"The Last Day, Part 2" received widespread acclaim, with several reviewers describing it as the season's best episode. Critics praised the reveal that Thawne had originally idolized the Flash and recreated Barry's accident because he wanted to become a hero, only to discover historical records identifying himself as the Reverse-Flash. Rowan Hale awarded the finale ten out of ten and wrote that the episode "turns Eobard's origin into a self-fulfilling tragedy without allowing the tragedy to excuse anything he has done".

Barry's refusal to accept responsibility for Thawne's choices was particularly praised, as was the reveal that Thawne's artificial speed was temporally tethered to Barry's. Critics also responded positively to Barry refusing opportunities to save Nora and Henry while traveling through time. Mara Ellison wrote that the finale's central argument was "not that Barry stops wanting his parents back, but that wanting something and choosing it are allowed to be different things".

The final confrontation at Mercury Labs was widely praised for involving the supporting characters rather than reducing the climax to another race between Barry and Thawne. Cisco separating their speed frequencies, Wally voluntarily using his temporal connection to tether Thawne, and Barry refusing to pursue Thawne when challenged to race were highlighted as resolutions to character developments established throughout the season. Barry ultimately casting Thawne into the Speed Force received particular acclaim.

The closing scenes involving Barry and Iris beginning a romantic relationship, Wally producing a brief burst of golden electricity and Cisco witnessing a blue speedster in another reality were positively received as setups for the second season. Thawne's survival in a timeless void received a more divided response; some critics considered it an effective acknowledgement that the character's story was unfinished, while others felt his apparent defeat would have been stronger without an immediate survival reveal.

Dan Stevens's performance received particular praise across the second half of the season. Critics noted the change in his portrayal after Thawne was unmasked, with the character becoming less physically mysterious while increasingly revealing his obsession with Barry. O'Brien was similarly praised for Barry's progression from an inexperienced hero driven by his mother's death into a character increasingly capable of separating grief from the choices he makes as the Flash.

The season's handling of Wally also received praise, particularly during its final episodes. Critics highlighted his survivor's guilt following Henry's death and the decision to depict his recovery as ongoing rather than resolving it through his involvement in the finale. McLaughlin's scenes with Kohli were frequently singled out, with several reviewers describing Wells and Wally's relationship as one of the unexpected strengths of the season.

Audience response

The premiere became one of Max's most-watched original drama debuts of 2027, with Warner Bros. Discovery reporting particularly strong completion rates during its first weekend of availability. Audience interest increased following "Faster", which marked the first extended confrontation between Barry and Reverse-Flash, and again during the two-part "Rogue War" storyline.

"Rogue War, Part 2" generated substantial discussion online following the deaths of most of the season's established Rogues. Leonard Snart and Lisa Snart trended on several social-media platforms following the episode's release, while viewers debated whether the characters could return through the season's developing time-travel storyline.

"The Man in Yellow" produced another increase in engagement following the reveal of Eobard Thawne's identity. Warner Bros. subsequently released previously withheld promotional material featuring Stevens without the Reverse-Flash mask.

"Out of Time" became the season's most-streamed episode during its first 24 hours of availability at that point, with discussion focusing on Barry's appearance during Nora's murder and Henry Allen's death. The two-part "The Last Day" finale subsequently surpassed it, with "The Last Day, Part 2" recording the season's highest opening-week viewership.

Audience response to the finale was predominantly positive. The Flash Museum, the first explicit use of the name "Speed Force", and Thawne's origin generated significant discussion following the episode. The final scenes involving Wally and Cisco also led to speculation concerning their roles in the second season.

External links

Template:First word/ The Flash season 1 at IMDbTemplate:EditAtWikidata

Category Flash (2027 TV series) seasons Category action television series Category superhero television series Category science fiction television series Category series about time travel Category series about parallel universes Category series based on DC Comics Category shows filmed in Vancouver Category (streaming service) original programming