Meanwhile, At The Hall of Justice
So with the world saved and the Justice League an official team, it's time they think about having a base of operations. For much of the film, the gang are working from Bruce's lakeside Batcave, but that won't do now that the whole world is looking to these heroes for hope and inspiration. What they need is a place where the people seeking their help can come, a place from which the League can gather and plan whatever future missions are needed to keep the world safe.
In one of the film's final scenes, Bruce, Diana, and Alfred enter the abandoned Wayne Manor. As they walk through the dilapidated building, they discuss the work necessary to make it again hospitable. Specifically, Bruce tells Diana he's thinking of getting a round table with six seats, to which she responds it must have "room for more." Fans will immediately recognize this as a nod towards the Hall of Justice, the Justice League's headquarters that first debuted in the Super Friends cartoon series and did, in fact, have a large table around which the League would meet. This seems to imply that in the DCEU, Wayne Manor will become the Hall of Justice, and that Diana plans to begin recruiting more heroes to their cause.
Who's The Fastest Man Alive?
As is custom with most superheroes films, and especially those trying to build a shared universe, Justice League has a couple of button scenes tacked on at the very end. The first comes midway through the credits and it features Superman and The Flash gearing up for a race, playing off the few times during the film where Flash finds himself impressed by the Man of Steel's quickness.
This is again one of those moments included for the diehard comic book fans since throughout DC Comics history, Superman and The Flash have competed in several races to decide who is the fastest man alive. Generally, The Flash (either the Barry Allen version or his successor, Wally West) will win these races, proving that even Superman is no match for those imbued with the Speed Force. This post-credit scene, however, doesn't reveal a winner, leaving it to audiences to debate just which of them is really the fastest man of the DCEU.
The Legion of Doom
The second and truly post-credit scene is the perfect coda on which to wrap a film that sees the Justice League coming together for the very first time. For every action, there is a reaction, and an assemblage of the greatest heroes in the DCEU is sure to draw the attention of some not very good people.
Once the credits finish rolling, a new scene opens on a prison riot at Arkham Asylum. The camera moves in on a bald inmate, presumably Lex Luthor, only for them to turn around and reveal it's a body double! The scene then cuts to a motorboat crossing the harbor and carrying Deathstroke, instantly recognizable in his iconic black and orange armor. He arrives at a larger ship where he's greeted by, of course, the real Lex Luthor. The two villains toast to Superman's return, and Luthor says he believes it's time they form a "league of their own." This is clearly a reference to the evil version of the Justice League comprised of DC Comics villains, referred to as either the Legion of Doom or the Injustice League. It's still too early to say for sure whether Warner Bros. plans to have the Injustice League ever actually appear, but it's a great tease all the same.