Justice League: The Snyder Cut - 10 Huge Moments From The Trailer You May Have Missed
3. Time-Travel And The Speed Force
During Justice League's DC FanDome panel, Snyder said that his movie will explore some of the Flash's "quantum" abilities, and it seems as if a first look at those can be seen here. In one of his many Vero posts, the filmmaker has alluded to the Fastest Man Alive travelling back in time during the final battle in order to save the team from being defeated by Steppenwolf.
That seems to be what's happening here as Barry Allen travels into the Speed Force (accidentally by the looks of it) and races into it. This would also tie into Snyder's Justice League sequel plans where the Flash was set to travel back to warn Bruce Wayne of Superman's fall, thereby tying all these confusing, dangling plot threads together.
It was also confirmed last night that The Flash is going to follow Barry as he travels through time to save his mother's life, but whether that will reference the events of this movie is hard to say, especially as it's highly unlikely even HBO Max will give Snyder the chance to continue this story.