The Flash season 1

The Flash
Season 1
Promotional poster
Showrunner	Maya Ellison
Starring	Dylan O'Brien Tati Gabrielle Sadie Sink 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 Maya Ellison. The season incorporates the Marvel Comics character Jean Grey as its principal antagonist through a fictional crossover arrangement between DC Studios, Warner Bros. Television, and Marvel Studios. It was produced by Warner Bros. Television and DC Studios in association with Mercury Pictures and Ellison House Productions, with Ellison serving as showrunner.

The season stars Dylan O'Brien as Barry Allen, a forensic scientist who develops superhuman speed after being struck by lightning during the catastrophic activation of an experimental particle accelerator. Tati Gabrielle, Sadie Sink, Victoria Pedretti, Xolo Maridueña, Kaitlyn Dever, Rahul Kohli, Caleb McLaughlin, Gugu Mbatha-Raw, Dan Stevens, Sterling K. Brown, and Jon Hamm also star. The story follows Barry as he becomes the masked hero known as the Flash while investigating the murder of his mother and the mysterious yellow-clad speedster responsible for it. His transformation coincides with the arrival of Jean Grey, a powerful telepath displaced from a dying parallel reality by the same energy that created Barry. Initially welcomed as an ally, Jean becomes increasingly convinced that uncontrolled emotion, grief, and human free will will inevitably destroy both Barry and Central City. Her connection to the cosmic Phoenix Force gradually intensifies, leading her to impose psychic peace upon the city and attempt to reconstruct her lost universe at the expense of Barry's world.

The season was structured as a serialized story divided into three movements, with its early episodes depicting Barry's transformation and Jean's integration into his circle, its middle episodes chronicling Jean's moral deterioration, and its final episodes focusing on the conflict between the Speed Force and the Phoenix Force. While several members of the Flash's traditional Rogues appear throughout the season, Jean serves as its central villain and emotional counterpoint to Barry. 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 and Sink's performances, the gradual development of Jean's antagonistic role, the season's visual effects, and its treatment of grief and personal autonomy, though some critics considered its 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, a Central City forensic scientist who gains superhuman speed following the destruction of the Mercury particle accelerator. Barry becomes a masked hero while investigating his mother's murder and learning to accept the grief he has spent much of his life attempting to escape.
• Tati Gabrielle as Iris West, a journalist and Barry's childhood friend who investigates Central City's emerging metahumans. Iris names Barry's alter ego the Flash and becomes one of the first people to reject Jean's psychic reality.
• Sadie Sink as Jean Grey / the Phoenix, a telepath and telekinetic displaced from a destroyed parallel universe. Initially an ally to Barry, Jean becomes the season's principal antagonist after concluding that suffering can only be eliminated by removing humanity's capacity for destructive choices.
• Victoria Pedretti as Caitlin Snow, a bioengineer at S.T.A.R. Labs who studies Barry and Jean's powers. Caitlin remains convinced that Jean can be separated from the Phoenix and opposes treating her solely as an enemy.
• Xolo Maridueña as Cisco Ramon, a mechanical engineer who develops Barry's suit, communication equipment, and technology capable of shielding the team from Jean's telepathy.
• Kaitlyn Dever as Patty Spivot, a Central City police detective assigned to investigate crimes involving metahumans. Patty reopens Nora Allen's murder and uncovers evidence of Eobard Thawne's presence in the past.
• Rahul Kohli as David Singh, the captain of the Central City Police Department's forensic division. Singh initially distrusts the Flash but becomes one of his most prominent supporters before being killed during the Phoenix crisis.
• Caleb McLaughlin as Wally West, Iris's younger brother and a university engineering student who assists Cisco during the later stages of Jean's occupation of Central City.
• Gugu Mbatha-Raw as Tina McGee, the director of S.T.A.R. Labs and creator of the Mercury particle accelerator. McGee feels responsible for the metahumans produced by the explosion and provides Jean with refuge following her arrival.
• Dan Stevens as Malcolm Gilmore / Eobard Thawne / Reverse-Flash, a speedster from the future who assumes the identity of a federal physicist. Thawne engineers Barry's transformation, murders Nora Allen, and brings Jean into Barry's universe as part of his attempt to weaponize the Phoenix Force.
• Sterling K. Brown as Joe West, Iris and Wally's father and Barry's adoptive parent. Joe serves as a Central City police captain and initially refuses to believe Barry's account of Nora's murder.
• Jon Hamm as Henry Allen, Barry's father, who was wrongfully convicted of murdering Nora and is exonerated near the end of the season.

Recurring

• Boyd Holbrook as Leonard Snart / Captain Cold, a calculating thief who develops weapons specifically designed to counter the Flash.
• Winston Duke as Mick Rory / Heat Wave, an arsonist and Snart's volatile criminal partner.
• Samara Weaving as Lisa Snart / Golden Glider, Leonard's younger sister and an expert pilot who joins the Rogues' assault on Jean's psychic amplifier.
• LaKeith Stanfield as Sam Scudder / Mirror Master, an optical engineer capable of traveling through reflective surfaces.
• Jessica Henwick as Linda Park, a reporter working alongside Iris at the Central City Citizen.
• David Harbour as General Wade Eiling, a military official seeking control over the metahumans created by the accelerator explosion.
• Keith David as the voice of Gorilla Grodd, an experimental gorilla whose intelligence and telepathic abilities are enhanced by energy released during Jean's arrival.
• Amy Adams as Nora Allen, Barry's mother, whose murder forms the central mystery of the season. Adams also portrays alternate versions of Nora created through the Speed Force and Jean's psychic illusions.

Guest

• Yahya Abdul-Mateen II as Mark Mardon / Weather Wizard, an atmospheric scientist capable of manipulating weather.
• Jesse Plemons as Danton Black / Multiplex, a scientist who can generate physical duplicates of himself.
• Lewis Pullman as Tony Woodward / Girder, a former construction worker whose body is transformed into metal.
• Riz Ahmed as Hector Hammond, a scientist whose telepathic powers amplify Jean's connection to Central City.
• Bill Skarsgård as James Jesse / the Trickster, a terrorist who attempts to destroy the Mercury reactor.
• Ming-Na Wen as Dr. Carla Tannhauser, Caitlin's mother and a specialist in neurological trauma.
• Clancy Brown as Judge Thomas Harkness, the judge who presided over Henry Allen's original trial.
• Shohreh Aghdashloo as Joan Williams, a physicist who helps Tina study the dimensional breach.
• Tony Todd as the voice of the Phoenix Force, the cosmic entity bonded to Jean.

Production

Development

On January 12, 2024, Mob Studios ordered The Flash to series with a 15 episode order for its first season. Alex Brow was announced as showrunner in June 2024.

Writing

Writing for the first season began in early 2024, following the series being ordered by Mob Studios. Brow, who developed the series and served as one of its principal writers, said that the initial stages of development focused heavily on establishing the season's long-term story and determining how closely the characters would follow their comic-book counterparts. In May 2024, Brow revealed that he was in the process of planning the season's overall timeline, stating that he wanted to put significant effort into ensuring that the characters were "completely faithful to the comics". He later confirmed that an outline for the entire first season had been completed.

During development, Brow prepared two different versions of the season's overarching storyline. One version was designed to function as a largely self-contained story in the event that the series was not renewed, while the second incorporated additional plot threads and unresolved storylines that could continue across multiple seasons. Brow explained that this approach allowed the writers to give the first season a complete narrative while still establishing material that could be expanded upon if further seasons were commissioned.

In July 2024, Brow revealed that the Reverse-Flash would serve as the primary antagonist of the first season. He said that the writers intended to avoid extensively repeating storylines previously adapted in the 2014 television series, instead developing a different interpretation of Barry Allen's early career and his conflict with Reverse-Flash. Brow nevertheless emphasized that the season would remain heavily influenced by the comics and would incorporate several recognizable elements from Flash mythology.

Brow also confirmed that multiple members of the Rogues would appear throughout the season, teasing that they would "cause some hell" for the Flash. Rather than immediately presenting the group as a fully established team, the season was developed to introduce several of its members individually before gradually connecting their respective storylines. Their presence was intended to expand the series beyond the central Reverse-Flash storyline and establish a wider collection of recurring enemies for Barry as he became more experienced as the Flash.

Casting

In June 2024, reports stated that Grant Gustin was in discussions to reprise his role from The CW series, however Brow announced that is not happening as he was looking for a different actor and has one already in talks and confirmed he would have information to reveal soon. Dylan O'Brien was confirmed as Barry Allen / Flash that August.

Filming

Principal photography began in Vancouver in April 2026 under the working title Mercury. Downtown Vancouver, Burnaby, and New Westminster were used to represent Central City, while additional exterior photography took place in Chicago. The S.T.A.R. Labs interiors, Central City Police Department, Mercury accelerator chamber, and Jean's psychic environment were constructed on soundstages in Burnaby.

The production team designed Central City as a bright and densely populated city rather than the desaturated urban environments used in several previous superhero television series. As Jean's influence expands, the city becomes increasingly symmetrical and visually controlled, with pedestrians, vehicles, and public displays moving in synchronized patterns. During the final episodes, physical sections of the Central City sets were combined with architecture from Jean's lost reality.

O'Brien's running scenes were filmed using treadmills, cable rigs, high-speed cameras, and extended practical sets. The production avoided relying exclusively on shots of a computer-generated figure surrounded by lightning. Cameras were mounted to accelerated tracking vehicles to allow O'Brien to perform within moving environments, while stunt performers portrayed Barry during collisions and rapid changes in direction.

Sink's Phoenix sequences were filmed using interactive red lighting, wind machines, suspended rigs, and controlled flame elements. Her final costume was designed to appear as if it were continuously forming from cosmic energy rather than functioning as conventional clothing. Filming concluded in February 2027 following additional photography for the final two episodes.

Visual effects

The visual effects were produced by Industrial Light & Magic, Wētā FX, Framestore, Rodeo FX, and Scanline VFX. The season contained approximately 2,900 visual effects shots, including Barry's speed, Jean's telepathy and telekinesis, the mirror dimension, the Speed Force, and the transformation of Central City during the final three episodes.

Barry's speed was represented through displaced air, pressure distortion, fragments of red lightning, and brief environmental reactions rather than a continuous trail. Objects close to Barry bend or vibrate as he passes, while scenes from his perspective use extended moments of near-stillness. The visual effects team developed different movement patterns for Thawne, whose speed produces reverse-moving debris and yellow lightning that appears to travel toward rather than away from his body.

Jean's telepathy was depicted through layered images, overlapping dialogue, and physical environments constructed from memories. The Phoenix Force initially appears as subtle fire beneath Jean's skin before developing into a large bird-shaped cosmic structure. The production avoided giving Jean a completely computer-generated appearance, retaining Sink's face and physical performance during most of the transformation.

The final confrontation combines the Speed Force with the Phoenix's psychic realm, referred to in production materials as the White Chamber. The environment was designed as an infinite red and white space containing fragments of Barry and Jean's memories. The sequence required more than eight months of post-production.

Music

Natalie Holt composed the season's score. Barry's theme uses rapidly repeating strings, electronic percussion, and a rising brass progression, while Jean's theme is built around a slower choral melody that becomes increasingly distorted as the Phoenix gains influence. The two themes are combined during the finale, with Barry's rhythm continuing beneath Jean's melody rather than replacing it.

Holt incorporated reversed instruments and altered recordings of human breathing into Thawne's theme. The Rogues were given variations of a shared musical motif, allowing their individual themes to form a single composition when the group assembles in the eleventh episode. The season's soundtrack was released digitally in two volumes, with the second volume including the extended track "Infinite Red" from the finale.

Marketing

The first promotional image depicted Barry standing inside the remains of the Mercury accelerator while a red-haired silhouette appeared within the lightning behind him. The image did not identify Jean Grey and led to speculation that the figure represented an alternate version of the Flash.

The cast and title were formally announced during a presentation at San Diego Comic-Con in July 2027. Sink appeared at the conclusion of the panel, confirming Jean's role in the series. The announcement trailer presented Jean as one of Barry's allies and did not reveal that she would become the season's principal antagonist. Dan Stevens was credited only as Malcolm Gilmore, preserving the reveal of Eobard Thawne.

A full trailer was released in August 2027. It focused on Barry's transformation, the emergence of metahumans, and Jean's warning that Central City would be destroyed by someone moving faster than light. The final shot showed the Phoenix reflected in Barry's eye. A second trailer released after the eighth episode revealed footage of Jean's psychic control over the city and used the tagline "You cannot outrun what is inside your mind."

Individual character posters were released for Barry, Iris, Jean, Joe, Caitlin, Cisco, Patty, Tina, and Gilmore. Jean's poster was later replaced with a Phoenix version following the release of "Fire in Her Blood".

Release

The season premiered on Max on October 1, 2027. Its 15 episodes were released weekly through January 7, 2028. The premiere was also broadcast on HBO as a promotional presentation, while the remaining episodes were exclusive to Max in the United States.

Episodes were released simultaneously in territories where Max was available. In other markets, the season was distributed through Warner Bros. Discovery's regional streaming and broadcast partners. The final three episodes were given limited theatrical screenings in selected cities, with "Dark Phoenix" and "Infinite Red" presented as a continuous feature.

Home media

The season was released on Ultra HD Blu-ray, Blu-ray, and DVD on May 14, 2028. The release included deleted scenes, audio commentaries for six episodes, a documentary about the Flash and Phoenix visual effects, screen tests featuring O'Brien and Sink, and an extended version of the finale.

Reception

Critical response

The first eight episodes received generally positive reviews, with critics praising the series' characterization of Barry Allen, its gradual expansion of Central City's metahuman population, and the season-long mystery surrounding the Reverse-Flash. The performances, action sequences and relationship between Barry, Joe and Iris were frequently singled out, while some reviewers criticized the length of the premiere and the amount of scientific exposition used in several early episodes. Reception became increasingly positive with "Faster" and the two-part "Rogue War", which several critics considered a significant escalation in the series' storytelling.

The pilot received positive reviews. Nathan Cole of Screen Current gave the episode four out of five stars, praising its decision to treat Nora Allen's murder as "the emotional engine of the series rather than convenient superhero backstory". He particularly praised Barry's relationship with Joe and the episode's final reveal of the Reverse-Flash observing Barry from an archive containing information from both the past and future. Cole was more critical of the episode's length, arguing that its multiple mysteries, the Mercury Labs accident and introduction of the supporting cast made the premiere "occasionally feel like two episodes compressed into one extremely ambitious pilot". Mara Ellison of The Television Ledger similarly praised the premiere's crime-procedural elements, writing that Barry being established as a forensic scientist before becoming a superhero gave the character "a reason to solve problems rather than simply outrun them".

"A Flash of Red" was praised for developing Barry's early limitations and introducing Leonard Snart as an opponent capable of anticipating his speed. 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; it requires knowing where he will run". Mercer praised the recurring idea that Barry's impulsiveness could be exploited, as well as his gradual acceptance of the Flash identity, though he felt the repeated failures of Barry's prototype equipment became slightly repetitive. Critics also responded positively to the humor between Barry and Cisco, with several noting that it prevented the episode's increasingly dangerous confrontations with Snart and Mick Rory from becoming overly grim.

"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 villain. Ward highlighted the scenes concerning his deceased sister Sarah and his relationship with Maya as giving the episode "an unusually human tragedy underneath a deliberately grotesque superpower". She also praised Barry defeating Danton by identifying the original through his heartbeat rather than overpowering his duplicates, arguing that it reinforced Barry's intelligence. Some reviewers considered the regenerative-science exposition overly dense, but generally praised the conclusion in which Danton assists Barry in containing the unstable tissue growth rather than being defeated through violence.

"Thin Air" received positive-to-mixed reviews. Critics praised Kyle Nimbus's ability to transform into toxic vapor and the episode's prison setting, with Daniel Reeves of The Episodic describing Nimbus as "one of the show's simplest villains conceptually and one of its most immediately threatening in execution". The episode's final sequence, in which the Reverse-Flash enters Danton's locked cell and kills him after discovering that he knows Barry's identity, received particular attention. Naomi Keller of Serial Screen called the scene "brutal, quiet and considerably more frightening than another citywide battle would have been", praising the decision to have Reverse-Flash lower Danton's body to the floor after stopping his heart. Keller nevertheless argued that killing Danton immediately after the previous episode had begun his redemption was "deliberately cruel but dramatically risky", as it removed one of the season's more morally complicated characters shortly after developing him.

"Faster" received widespread acclaim and was frequently described as the strongest episode of the season to that point. Rowan Hale of Screen Current gave the episode nine out of ten, praising the decision to place Barry and the Reverse-Flash in direct conflict significantly earlier than expected. Hale described their first extended speedster battle as "less a superhero fight than an abusive lesson", noting that Reverse-Flash repeatedly allows Barry to improve while remaining capable of killing him. The confrontation outside Barry's childhood home was particularly praised, including Barry's realization that his enemy does not actually want him dead. Critics also praised Joe finally telling Barry that he believes his account of Nora's murder. Leah Price of The Television Ledger wrote that the episode's central idea—Barry learning that becoming faster does not necessarily mean becoming better—gave the action "an actual dramatic purpose beyond determining which colored lightning moves quickest".

"Storm Warning" also received positive reviews. Critics praised the episode for giving Joe a central role through his history with Mark Mardon and his brother Clyde. Theo Grant of The Episodic awarded it four out of five stars, calling the confrontation between Joe and Mardon at the freight yard "one of the season's best scenes without Barry throwing a single punch". Barry's attempt to break apart the storm by running a counter-circulation around Central City was praised for depicting his powers on a larger scale while maintaining physical consequences, including his heart temporarily stopping during the attempt. Some reviewers felt Mardon's motivation relied heavily on his anger toward Joe, but praised the script for refusing to portray Joe's shooting of Clyde as an obvious moral mistake.

"Rogue War, Part 1" received strong reviews for bringing together several previously established antagonists. Critics praised the conflict between Leonard Snart's group and Sam Scudder's alliance with Mardon and Roscoe Dillon, as well as Lisa Snart's introduction into the conflict. Rebecca Shaw of Frame & Panel gave the episode an A−, writing that its greatest strength was allowing its villains "to possess relationships, grudges and loyalties that exist independently of the Flash". The chaotic fight sequences at Mercury Labs and the glassworks were praised, though some critics felt the number of super-powered characters occasionally made the action difficult to follow. The cliffhanger, in which Scudder traps Barry inside a dimension composed of reflected spaces before Snart destroys his apparent exit, was widely praised. Shaw called the final image of Barry surrounded by windows into Central City but unable to reach anyone "the cleverest possible predicament for a hero whose defining ability is running somewhere".

"Rogue War, Part 2" received widespread acclaim, with several critics describing it as the best episode of the first eight. Amanda Keene of Serial Screen awarded it nine-and-a-half out of ten, praising Barry's escape from Mirror Space, the temporary cooperation between the Flash and the six Rogues, and the subsequent arrival of the Reverse-Flash. Critics particularly praised the tonal shift after Reverse-Flash enters the conflict and begins killing the Rogues individually, with Keene writing that the episode "allows the audience to spend two episodes treating these people as dangerous supervillains before introducing something so much worse that their survival suddenly matters". Leonard Snart's death received particular praise, especially his final warning to Barry not to allow Reverse-Flash to take him as well.

Marcus Venn of The Television Ledger praised the final battle between Barry and Reverse-Flash, but noted that its effectiveness came from Barry's emotional defeat rather than spectacle, writing that "Barry spends the episode getting faster and still discovers that he is nowhere near ready". Venn also praised the reveal of Barry's identity to the Rogues and Reverse-Flash's assertion that Barry "matters", describing the latter as an effective expansion of the season's central mystery. The episode's unusually high body count divided some reviewers, who questioned whether eliminating several established Rogues in a single episode reduced their long-term potential; however, the deaths were generally considered effective in establishing Reverse-Flash as the season's primary threat.

Audience viewership

The premiere became one of Max's most-watched original drama debuts of 2027. Viewership increased following the release of "Fire in Her Blood", which revealed Jean as the principal antagonist, and again during the final three episodes. "Infinite Red" became the season's most-streamed episode during its first week of availability.

Jean's occupation of Central City and the reveal of Thawne generated significant discussion online. The Rogues episode also received a strong audience response, leading to speculation that the group would return in a larger capacity during the second season.

Accolades

Year	Award	Category	Nominee(s)	Result
2028	Primetime Creative Arts Emmy Awards	Outstanding Special Visual Effects in a Season or a Movie	The Flash	Won
		Outstanding Music Composition for a Series	Natalie Holt for "Infinite Red"	Nominated
		Outstanding Stunt Coordination for a Drama Series	The Flash	Nominated
	Saturn Awards	Best Superhero Television Series	The Flash	Won
		Best Supporting Actress in a Television Series	Sadie Sink	Won
	Critics' Choice Television Awards	Best Actress in a Drama Series	Sadie Sink	Nominated
	Screen Actors Guild Awards	Outstanding Performance by a Stunt Ensemble in a Television Series	The Flash	Nominated

External links

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