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.

Iris is pushed to the limit as she seeks to uncover the mysterious truth about Psych; Barry initiates a new training system, that could potentially backfire, with devastating consequences; Joe and Cisco make life-altering decisions.

Barry and Iris come together to try and stop a dangerous force from destroying Central City.

John Diggle arrives in Central City with a weapon to help Barry stop the Godspeed War. Meanwhile, Allegra and Ultraviolet's new bond is put to the ultimate test, while Joe and Kristen Kramer are hunted by a former colleague of hers.

Barry meets Black Lightning at the Hall of Justice after things take a dire turn with Despero. Iris suspects something is off with Despero's vision of the future so she seeks help from a powerful ally.

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.

Barry's desire to keep Team Flash safe is tested when Frost recklessly courts danger as she tries to stop the "Black Flame," meanwhile, Iris tries to help a teen girl reunite with her mother but unintentionally does more harm than good.

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.