Superhero fans, rejoice: A new "Justice League" trailer and movie poster have been revealed at Comic-Con in San Diego.

Time reported that the trailer released Saturday "hints at the appearance of a mysterious hero," possibly Superman or a Green Lantern.

The poster, which features Batman (Ben Affleck), Wonder Woman (Gal Gadot), the Flash (Ezra Miller), Cyborg (Ray Fisher) and Aquaman (Jason Momoa), features the words, "You can't save the world alone."