<P> The fourth season of the American television series The Flash, which is based on the DC Comics character Barry Allen / Flash, follows a crime scene investigator with superhuman speed who fights criminals, including others who have also gained superhuman abilities . It is set in the Arrowverse, sharing continuity with the other television series of the universe, and is a spin - off of Arrow . The season is produced by Berlanti Productions, Warner Bros. Television, and DC Entertainment, with Andrew Kreisberg and Todd Helbing serving as showrunners . </P> <P> The season was ordered in January 2017, and filming began that July . Grant Gustin stars as Barry, with principal cast members Candice Patton, Danielle Panabaker, Carlos Valdes, Keiynan Lonsdale, Tom Cavanagh, and Jesse L. Martin also returning from previous seasons, and are joined by Neil Sandilands . </P> <P> The fourth season began airing on October 10, 2017, on The CW . </P> <Table> <Tr> <Th> No . overall </Th> <Th> No. in season </Th> <Th> Title </Th> <Th> Directed by </Th> <Th> Written by </Th> <Th> Original air date </Th> <Th> Prod . code </Th> <Th> U.S. viewers (millions) </Th> </Tr> <Tr> <Th> 70 </Th> <Td> </Td> <Td> "The Flash Reborn" </Td> <Td> Glen Winter </Td> <Td> Story by: Andrew Kreisberg Teleplay by: Todd Helbing & Eric Wallace </Td> <Td> October 10, 2017 (2017 - 10 - 10) </Td> <Td> T27. 13401 </Td> <Td> 2.84 </Td> </Tr> <Tr> <Td_colspan="8"> Iris has been aiding Team Flash in Central City for six months, but refusing to grieve Barry . A flying Samurai with superpowers appears in Central City, threatening to destroy the city if the real Flash does not face him . Cisco reveals he has formulated a way to bring back Barry without destabilizing the Speed Force, and tracks down Caitlin for help . Against Iris' direction, Team Flash successfully returns Barry, who appears rambling random statements and continually writing symbols on walls . Wally engages the Samurai, but is defeated . Cisco deciphers Barry's writings and finds an apparently meaningless sentence . In an attempt to recover Barry's memories, Iris gives herself up to the Samurai . The plan works and Barry speeds away, rescuing Iris and defeating the Samurai, who is revealed to be a robot . Caitlin rejoins Team Flash, but is revealed to have been working for a mobster called Amunet at the bar, while also continuing to prevent the Killer Frost personality from emerging . The "Samuroid" is revealed to have been controlled by the Thinker, whose plan was to draw out the Flash for his next schemes . </Td> </Tr> <Tr> <Th> 71 </Th> <Td> </Td> <Td> "Mixed Signals" </Td> <Td> Alexandra La Roche </Td> <Td> Jonathan Butler & Gabriel Garza </Td> <Td> October 17, 2017 (2017 - 10 - 17) </Td> <Td> T27. 13402 </Td> <Td> 2.54 </Td> </Tr> <Tr> <Td_colspan="8"> When Barry, Joe, and Cisco report to a crime scene, they discover remnants of a mysterious code . Cisco presents Barry with a technologically advanced suit, intended to facilitate his activities . He tests it out, trying to save someone from a haywire car, caused by metahuman Ramsey Deacon . Gypsy arrives on Earth - 1 for a date with Cisco, who is forced to cancel it so as to focus on Deacon . Acting on a suggestion from Caitlin, Iris signs her and Barry up for couples therapy to sort out their relationship . Deacon kidnaps a witness, who was previously a member of a tech team who sold him out of his idea . Barry and Wally go to save him, but Deacon uses his abilities to send Barry's suit haywire . On Iris's instructions, Barry throws lightning at himself, shorting out his suit . He then incapacitates Deacon, who is locked up in the meta wing of Iron Heights, revealed to be part of the Thinker's plan . Cisco finally goes out with Gypsy . Wondering how Deacon gained his powers being absent during the particle accelerator incident, Barry and Joe learn from Deacon that there are "others". </Td> </Tr> <Tr> <Th> 72 </Th> <Td> </Td> <Td> "Luck Be a Lady" </Td> <Td> Armen V. Kevorkian </Td> <Td> Sam Chalsen & Judalina Neira </Td> <Td> October 24, 2017 (2017 - 10 - 24) </Td> <Td> T27. 13403 </Td> <Td> 2.62 </Td> </Tr> <Tr> <Td_colspan="8"> In flashbacks, the Thinker observes Becky Sharpe, a woman with seemingly unending bad luck, and determines that she will be easily manipulated . In the present, Becky robs a bank, and gets away when Barry slips on marbles . Harry arrives from Earth - 2, and tells Wally that Jesse has decided to break up in order to focus on her vigilantism . Cisco deduces that Becky is a metahuman with the power of favorable luck while inducing misfortune to others . Barry realizes that the portal he used to escape the Speed Force exposed an entire busload of people, including Becky and Deacon, to transformative dark matter . Harry informs Cisco that Jesse has expelled him from her crime - fighting team due to his attitude . Becky's powers expand out of control, reactivating the particle accelerator, which Harry deliberately allows, nullifying Becky's powers and leading to her incarceration . Cisco and Harry identify twelve new metahumans created on the bus, and the latter suspects that an unknown party has manipulated events surrounding Barry's return . Wally decides to leave on a journey to find himself . The Thinker is revealed to be spying on S.T.A.R. Labs through the "Samuroid" helmet . Joe learns Cecile is pregnant . </Td> </Tr> <Tr> <Th> 73 </Th> <Td> </Td> <Td> "Elongated Journey Into Night" </Td> <Td> Tom Cavanagh </Td> <Td> Sterling Gates & Thomas Pound </Td> <Td> October 31, 2017 (2017 - 10 - 31) </Td> <Td> T27. 13404 </Td> <Td> 1.99 </Td> </Tr> <Tr> <Td_colspan="8"> Gypsy's father, Breacher, attacks Cisco, vowing to hunt and kill him in 24 hours, allowing the romance should he survive . Team Flash learns that the bus driver was murdered and tracks down another passenger, Ralph Dibny, former corrupt CCPD detective exposed by Barry and currently an infamous private investigator . As two thugs attack Dibny, he is revealed to have the power to stretch . Caitlin stabilizes his powers with a serum . The team learns that Ralph has been blackmailing Mayor Bellows for adultery, with the latter revealed to have hired the thugs . Barry confronts Ralph for his actions while the latter scolds him, claiming to have been a "good cop". He later stops blackmailing Bellows, who still attempts to kill him while Breacher mistakes the former for a Plastoid, the species that invaded Earth - 19 previously, and attacks him . Cisco intervenes and saves Ralph, whom Barry, having revealed his alter - ego, convinces to help arrest an escaping Bellows . Admiring Cisco's gallantry, Breacher allows the relationship . Barry recruits Ralph for Team Flash and learns that someone named DeVoe instructed Ralph to watch Bellows . Barry remembers that Abra Kadabra and Savitar both mentioned DeVoe . Meanwhile, Caitlin finds a message on her apartment door . </Td> </Tr> <Tr> <Th> 74 </Th> <Td> 5 </Td> <Td> "Girls Night Out" </Td> <Td> Laura Belsey </Td> <Td> Lauren Certo & Kristen Kim </Td> <Td> November 7, 2017 (2017 - 11 - 07) </Td> <Td> T27. 13405 </Td> <Td> 2.38 </Td> </Tr> <Tr> <Td_colspan="8"> While failing to track DeVoe, Team Flash is visited by Felicity, who joins Iris's bachelorette party . Mocking Cisco's plans for Barry's bachelor party, Ralph takes the men to a strip club, where they learn that Cecile's daughter, Joanie, is working . Joe confronts her, who states she is only doing feminist research . Ralph incites a brawl, leading to the men's arrest until Harry posts bail . Meanwhile, Amunet's enforcer, Norvock, demands Caitlin's return and attacks the women when she refuses . Killer Frost emerges and repels him, later telling Iris that Caitlin accepted Amunet's employment in exchange for the means to control Frost . Learning that Amunet is holding a metahuman she calls "the Weeper", whose tears are a strong narcotic, prisoner and intends to sell him, Iris's party decides to stop her . Though Caitlin refuses to join, she attacks Amunet when seeing her friends in danger . Using a strong magnet, the team robs Amunet's metal shards, leaving her powerless . Iris dissuades Frost from killing Amunet, who promises revenge . Both parties refuse to tell each other about their adventures . Iris asks Caitlin to be her maid of honor while Joe convinces Joanie to tell Cecile about her research . DeVoe captures the Weeper . </Td> </Tr> <Tr> <Th> 75 </Th> <Td> 6 </Td> <Td> "When Harry Met Harry ..." </Td> <Td> Brent Crowell </Td> <Td> Jonathan Butler & Gabriel Garza </Td> <Td> November 14, 2017 (2017 - 11 - 14) </Td> <Td> T27. 13406 </Td> <Td> 2.46 </Td> </Tr> <Tr> <Td_colspan="8"> Barry trains Ralph to use his abilities, with Cisco making a stretchable suit for him . Another bus metahuman, a Lakota Sioux Native named Mina Chayton, who can animate statues, starts attacking Central City & stealing pieces of a Black Bison necklace, which she claims belongs to her tribe . When Barry and Ralph catch up to her, she attacks Barry with a caveman statue and attempts a getaway . Ralph chooses to stop her, but a little girl is injured in the process . Ralph regrets his actions, but is comforted by Barry . Chayton escapes CCPD, going after the last necklace piece held at the museum . When Barry and Ralph confront her, she brings a dinosaur skeleton to life . Barry arrests Chayton while Ralph saves a security guard from the skeleton . Later, Ralph reveals he mailed the necklace back to Chayton's tribe, before visiting the little girl in the hospital, using his abilities to entertain her . Meanwhile, Harry, trying to make friends, works with his doppelgangers of alternate Earths, The Council of Wells . They figure out that DeVoe is a man named Clifford DeVoe . Barry and Joe head to DeVoe's house, to find out that he is a middle - aged man in a wheelchair . </Td> </Tr> <Tr> <Th> 76 </Th> <Td> 7 </Td> <Td> "Therefore I Am" </Td> <Td> David McWhirter </Td> <Td> Eric Wallace & Thomas Pound </Td> <Td> November 21, 2017 (2017 - 11 - 21) </Td> <Td> T27. 13407 </Td> <Td> 2.20 </Td> </Tr> <Tr> <Td_colspan="8"> Barry and Joe interrogate DeVoe and his wife to try and get more information . In flashbacks, DeVoe and his wife build a thinking cap to improve his brain capacity, powering it through the particle accelerator explosion . DeVoe's increased brain power accelerates his amyotrophic lateral sclerosis, forcing his wife to build him a special chair to keep him alive . Barry discovers the camera in the Samuroid head and confronts DeVoe, who reveals his true identity, leading to Cisco dubbing him "The Thinker". Wally returns to Team Flash from Blue Valley . </Td> </Tr> <Tr> <Th> 77 </Th> <Td> 8 </Td> <Td> "Crisis on Earth - X, Part 3" </Td> <Td> Dermott Downs </Td> <Td> Story by: Andrew Kreisberg & Marc Guggenheim Teleplay by: Todd Helbing </Td> <Td> November 28, 2017 (2017 - 11 - 28) </Td> <Td> T27. 13408 </Td> <Td> 2.82 </Td> </Tr> <Tr> <Td_colspan="8"> <P> Barry, Oliver, Sara, Alex, Martin and Jax wake up in a Nazi concentration camp on Earth - X, with power dampening handcuffs . The arriving SS - Sturmbannführer is revealed to be the Earth - X doppelgänger of Quentin Lance, who takes them away for execution, before they are saved by Citizen Cold (the Earth - X doppelgänger of Leonard Snart) and The Ray (Ray Terrill). Snart and Terrill take them to the underground headquarter of the Freedom Fighters, where the team meets the resistance movement's leader General Winn Schott (Winn Schott's Earth - X doppelgänger). They learned that the only way back to Earth - 1 is through a temporal gateway in a Nazi facility, which Schott plans to blow up to strand Dark Arrow (Oliver's Earth - X doppelgänger) on Earth - 1 . Oliver disguises himself as Dark Arrow to infiltrate the facility, discovers the Nazi's doomsday device against parallel Earths is a militarized timeship called Wellenreiter, and saves a prisoner (who is Felicity's Earth - X doppelgänger) from Quentin . Barry and Ray battle the Freedom Fighters' Red Tornado to stop it from destroying the temporal gateway, while the rest of the team enters the facility . In attempting to reactivate the gateway's portal, Stein is shot and gravely wounded . Back on Earth - 1, Thawne prepares to perform surgery on Kara to save Overgirl at S.T.A.R. Labs . Felicity and Iris try to stop him, but are captured . </P> This episode continues a crossover event that begins on Supergirl season 3 episode 8 and Arrow season 6 episode 8, and concludes on Legends of Tomorrow season 3 episode 8 . </Td> </Tr> <Tr> <Th> 78 </Th> <Td> 9 </Td> <Td> "Don't Run" </Td> <Td> Stefan Pleszczynski </Td> <Td> Sam Chalsen & Judalina Neira </Td> <Td> December 5, 2017 (2017 - 12 - 05) </Td> <Td> T27. 13409 </Td> <Td> 2.22 </Td> </Tr> <Tr> <Td_colspan="8"> While out Christmas shopping, Barry is ambushed and kidnapped by DeVoe while Caitlin is kidnapped from Jitters by Amunet . Iris claims they have to look for both of them, despite Wells' claim that they have insufficient time and resources and that they can only afford to search for one . Barry is held in DeVoe's lair . Caitlin is forced by Amunet to perform surgery on a metahuman named Dominic Lanse, who can read minds . They try to escape, but Amunet blocks their exit . Caitlin manages to briefly incapacitate Amunet, and she and Dominic flee the building they are being held in . Once outside, they are rescued by Cisco and Ralph, as Iris has chosen to focus on finding Caitlin . Barry manages to escape from DeVoe . Team Flash celebrates Christmas at the West house and Dominic joins them . Barry gets a security alert from his apartment . When he arrives, he receives a phone call from Dominic, who reveals that Amunet re-kidnapped Dominic and DeVoe has transferred his consciousness into Dominic's body . Barry discovers DeVoe's original body dead on his apartment floor and he realizes DeVoe has framed him for his "murder"; the police arrive, and Barry lets himself get arrested, not wanting to leave Iris again . </Td> </Tr> <Tr> <Th> 79 </Th> <Td> 10 </Td> <Td> "The Trial of The Flash" </Td> <Td> Philip Chipera </Td> <Td> Lauren Certo & Kristen Kim </Td> <Td> January 16, 2018 (2018 - 01 - 16) </Td> <Td> TBA </Td> <Td> TBD </Td> </Tr> <Tr> <Th> 80 </Th> <Td> 11 </Td> <Td> "The Elongated Knight Rises" </Td> <Td> Alexandra La Roche </Td> <Td> Sterling Gates & Thomas Pound </Td> <Td> January 23, 2018 (2018 - 01 - 23) </Td> <Td> TBA </Td> <Td> TBD </Td> </Tr> </Table>

Is it going to be a season 4 of the flash