Barry Allen uses his super speed to change the past, but his attempt to save his family creates a world without super heroes, forcing him to race for his life in order to save the future.Barry Allen uses his super speed to change the past, but his attempt to save his family creates a world without super heroes, forcing him to race for his life in order to save the future.Barry Allen uses his super speed to change the past, but his attempt to save his family creates a world without super heroes, forcing him to race for his life in order to save the future.