Faced with the news of his impending death, Barry's resiliency suffers as he struggles to fight fate. Meanwhile, Cecile's career as a D.A. conflicts with her identity when she crosses paths with a villainous meta-human.

Barry and Iris greet their future children, XS and Bart, only for a shocking secret to threaten their new familial harmony. Meanwhile, the Godspeed war intensifies and threatens to destroy Central City.

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

The Flash, the fastest man alive, is tasked with his greatest challenge yet, to save the timeline and save existence. Friends old and new gather for an epic battle to save Central City, one last time.