The Flash story begins when Barry Allen (Ezra Miller) uses his superpowers to travel through time to change past events. But when his attempt to save his family accidentally changes the future, Barry is trapped in a reality where General Zod has returned and threatens to destroy everything, but no superhero is standing up to save him… Unless Barry can convince a very different Batman and rescue an imprisoned Kryptonian… who may not be the one he's really looking for. To save the present world and return to the future he once knew, Barry's only hope is to race for his life. But will that ultimate sacrifice be enough to return the world to the way it was?