In Batman v Superman: Dawn of Justice, when Wonder Woman (Gal Gadot) is viewing the "Metahuman Thesis" files Bruce Wayne (Ben Affleck) obtained illegally from LexCorp, she comes across a series of videos with Silas Stone (Joe Morton, Jr.), a S.T.A.R. Labs scientist.
He's conducting experiments on his son, Victor (Ray Fisher), who we see in the background. Victor's missing most of his body after being in a horrible accident. Silas was able to keep Victor alive with his immense talents and skills in technology, but when his son's health begins to deteriorate rapidly, the desperate father activates a Mother Box. The mysterious, moving box, which is referred to as an "alien artifact," gravitates toward Victor, fuses with him, and rebuilds him into a cyborg.
Additionally, three Mother Boxes appeared in the "Communion" deleted scene that Warner Bros. officially released back in February. In it, we got a glimpse of Darkseid's uncle, Steppenwolf, holding the boxes.
So, what's the 411 on the cinematic version of the Mother Boxes?
"These Mother Boxes are best used and work in threes, and back before there was a history, these Mother Boxes – this is an Amazonian Mother Box, this is Atlantean, and this is mankind," producer Charles Roven explained to Comicbook.com and other press during a Justice League set visit. "So when –again, let me just set this over here. So sort of back before history, mankind, the Atlanteans, before they were underwater, the Amazons, and actually the old gods, teamed together and decided that, based on an event that happened, these Mother Boxes were going to be placed in the care of as I said, the Amazons, mankind, and the Atlanteans. So that allowed us to get into some of those environments in our story."
In DC Comics, Mother Boxes attach themselves to a host and help them in whatever way they need. With the "New 52" reboot, Cyborg's backstory was adjusted to include powers granted by a Mother Box.
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.
The film is being directed by Zack Snyder, based on a screenplay by Chris Terrio. The cast features Ben Affleck as Bruce Wayne/Batman, Henry Cavill as Clark Kent/Superman, Gal Gadot as Diana Prince/Wonder Woman, Ezra Miller as Barry Allen/The Flash, Jason Momoa as Arthur Curry/Aquaman, Ray Fisher as Victor Stone/Cyborg, Amy Adams as Lois Lane, Jesse Eisenberg as Lex Luthor, Jeremy Irons as Alfred Pennyworth, J. K. Simmons as Commissioner James Gordon, and Amber Heard as Mera.
Justice League will open in theaters on November 17, 2017.