When Barry Allen’s attempt to save his family goes horribly wrong, he unintentionally changes the course of history, trapping himself in an alternate reality. In this new world, General Zod has returned, and there are no superheroes to defend against the impending destruction. With the fate of the world hanging in the balance, Barry realizes that the only way to fix the timeline and return to the future he knows is by racing against time itself. But in a reality without Superman or other familiar heroes, Barry must confront whether he can make the ultimate sacrifice to reset the universe—if it’s even possible.