Barry precisa lidar com a última ameaça do Flash Reverso a um dos membros do grupo. Para piorar as coisas, o Dr. Wells soltou Grodd na cidade a fim de distrair tanto o velocista escarlate quanto o seu time. Joe, Barry e Cisco vão até os esgotos para capturar Grodd, mas o gorila rapidamente ganha vantagem após sequestrar Joe. Para completar, Barry e Iris tem uma conversa franca.

Wells apresenta a Barry uma escolha que pode mudar vidas. Enquanto isso, o Dr. Martin Stein e Ronnie Raymond retornam para ajudar a STAR Labs com esta última luta.

Barry e o time descobrem que o Capitão Frio foi sequestrado, portanto, formam uma aliança pouco tranquila com a irmã de Snart, Lisa. No entanto, Barry se sente traído ao descobrir que Snart está trabalhando com seu pai, Lewis, em um roubo. Para completar, Joe precisa tomar uma difícil decisão.

Após os eventos recentes, Barry decide que é hora de confrontar Zoom e, para isso, cria um plano arriscado. Caitlin fica ao lado de Jay, que acredita que é perigoso demais bater de frente com o inimigo, porém Iris mostra seu apoio e traz consigo um aliado inesperado. Para completar, veremos como era a vida de Harrison Wells na Terra-2, ou seja, antes de ter cruzado a ponte entre os dois universos.

Mark Mardon, o Mago do Tempo, reaparece para libertar Leonard Snart, o Capitão Frio e James Jesse, o Trapaceiro, da prisão Iron Heights. Barry precisa deter o trio de vilões no dia de Natal. Enquanto isso, Joe e Iris conhecem Wally West.

Barry se alia a Wells para encontrar uma forma de fechar as fendas, mas são distraídos por um metahumano com o apelido de Tar Pit (no português, Poço de Piche), que pode se transformar em asfalto líquido. Enquanto isso, Iris se mostra preocupada com a segurança de Wally após descobrir sobre seu hobby com corridas. Ele se recusa a parar e ela toma uma atitude ousada que a coloca em risco.

As Eva becomes more powerful, Barry and team must find a way to stop her. They are shocked when an old friend - Sue Dearbon risks her life to help.

Cisco and Chester travel back in time and get stuck in 1998, repeating the same day over and over again. The key to returning home is at Chester's childhood home but he refuses to visit.

After a devastating betrayal, Barry turns to Timeless Wells for help. Meanwhile, Iris leads Team Citizen down a dangerous road in search of answers, and Cisco confides his biggest fear to Kamilla.

Cisco and Kamilla tell the team they are leaving Central City. However, Barry, Iris and Caitlin don't have much time to digest the news because a new version of Rainbow Raider strikes and OG Team Flash must join together one final time to save the city.

When an army of Godspeeds attack Central City, Barry and Iris must put their family plans on hold and focus on the latest threat to their home. Meanwhile, Chillblaine is released from prison and claims to be reformed but Frost has her doubts.

The Flash enlists a host of speedster allies, including Iris and his children from the future - Bart and Nora West-Allen - to end the speedster war and defeat a deadly new adversary: the villainous Godspeed.

Despero warns The Flash that great tragedies will befall the speedster and cause him to lose his mind. Once that happens, Armageddon will begin. Determined to prove Despero wrong, Barry doubles down on proving his innocence but a devastating revelation from Iris pushes him to the edge and sends him to seek counsel from Black Lightning.

After returning home from a visit for their parent's vow renewal, Bart and Nora quickly realize that things are not exactly as they left them. The duo race to repair any fissures in the timeline and restore everything back to the way it is supposed to be.

Barry and Team Flash get closer to figuring out the Fire Meta but no closer to finding him meanwhile Iris, needing a distraction, follows a story to Coast City.

With a new Meta terrorizing the city, Joe lends a hand to the local authorities, meanwhile Barry gets an assist from Cecille who helps to track the mass murderer.

The Flash gets an assist from XS. Meanwhile, CCPD enlists Chester for help when a mysterious device is found at a crime scene.

With a new speedster in town, The Flash gets much more than he bargained for, meanwhile Cecile's powers experience a growth spurt allowing her to aid Team Flash on an entirely different level.

With The Flash still reeling from everything that just happened, the rest of the team rallies to support him when he needs it the most.

Barry feels guilty for what happened to Caitlin, and Mark comes up with a plan that makes everyone skeptical. Meanwhile, Red Death looms in Central City and commands that failure is not an option. Joe asks Cecile to make a choice that leads Cecile to think about the greater good. Allegra and Chester take a step in a new direction. Lastly, old friends pay an unexpected visit to S.T.A.R. Labs.

As the Red Death wreaks havoc on Central City, Barry and Iris come up with a plan and turn to Cecile for help. Barry is faced with what he thinks was his greatest mistake and the Red Death's greatest success. Khione wants to help Team Flash, but Barry can't risk losing her. Joe gives Barry a much-needed pep talk.

A seemingly simple mold inspection at S.T.A.R. Labs leads to unexpected time anomalies. Barry and Iris try to make sense of the confusion - and figure out how to get back to their reality. Chester admits a secret to Allegra, which makes things awkward between the two, and Allegra relies on Cecile to act as a buffer. Meanwhile, Khione meets with an old friend of Team Flash.