Here's the official synopsis for Justice League -
"Fueled by his restored faith in humanity and inspired by Superman’s selfless act, Bruce Wayne enlists the help of his newfound ally, Diana Prince, to face an even greater enemy. Together, Batman and Wonder Woman work quickly to find and recruit a team of metahumans to stand against this newly awakened threat. But despite the formation of this unprecedented league of heroes—Batman, Wonder Woman, Aquaman, Cyborg and The Flash—it may already be too late to save the planet from an assault of catastrophic proportions.
Directed by Zack Snyder, this marks the big screen debut of the Justice League, featuring an all-star lineup: Ben Affleck, Henry Cavill, Gal Gadot, Jason Momoa, Ezra Miller and Ray Fisher." - Warner Bros.