During the Warner Bros. presentation at San Diego Comic-Con, the studio teased its upcoming DC Extended Universe films by revealing a series of titles, Justice League, The Batman and Shazam among them. The studio had already announced it was making most of these films, but one in particular came as a surprise to the audience: "Flashpoint." The title is reference to a plot line in the comic books that apparently will be the basis for the upcoming movie about the Flash, starring Ezra Miller.
Here's a spoiler-free explanation of what happens in Flashpoint.
Flashpoint isn't just a storyline about the Flash. It was an event that changed the entire DC universe across comic books. In the story, Barry Allen (a.k.a. The Flash) wakes up in an unrecognizable world. He doesn't have the power of super speed anymore, and the Justice League doesn't exist. Nobody seems to notice that the world has completely changed, except for Barry.
Looking for answers — and a way to get his powers back — Barry tries to hunt down the members of the Justice League and doesn't necessarily like what he finds.
A Flashpoint movie could set up an entire parallel universe, even with new actors playing some of the familiar roles. More importantly, it could subvert a by-then familiar cinematic universe. Because by the time The Flash finally premieres, Justice League, Aquaman, Shazam! and Wonder Woman 2 will have already hit movie theaters.