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.

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.

An opportunity presents itself for The Flash to end his lifelong battle with Reverse Flash for good, but the payoff could be too much for Barry and team to handle. Meanwhile, Mia Queen drops in from the future looking to save a lost loved one, and she won't let anything stand in her way.

The Flash and team are in for the fight of their lives, meanwhile, Iris discovers the cause of her time sickness.