Spoilers for Justice League follow below.
Justice League is now finally in theaters, which means fans can pore over every detail of the highly anticipated DC Comics adaptation. But some may be coming away from the film with a few questions, especially as it pertains to the movie’s MacGuffin—those darn Mother Boxes. Indeed, as teased in Batman v Superman: Dawn of Justice, Mother Boxes play a major role in the plot of Justice League, and are the driving force of the film’s villain Steppenwolf. So below, we’ve put together a rundown of what Mother Boxes are, what they do, their comics origins, and what they mean for the DCEU.
The concept of Mother Boxes in the DC film universe was first teased in Batman v Superman. In the sequence teasing Cyborg’s (Ray Fisher) origin story we saw that his father was using a Mother Box to power him, and in a deleted scene released online around the time of BvS’s release, we saw Lex Luthor (Jesse Eisenberg) communicating with Steppenwolf via hologram, during which Steppenwolf was holding three Mother Boxes in his hands.
As we learn in Justice League, the Mother Boxes are major sources of power. When Steppenwolf first attacked Earth thousands of years ago, he had combined the three Mother Boxes to form Unity, which gave him tremendous power. But a union of Amazonians, Atlanteans, and Men fought Steppenwolf off, forcing him into retreat without his Mother Boxes. At the end of the battle, Earth’s three groups agreed to separate the Mother Boxes and hide them away. One went to the Amazons for safekeeping in Themyscira, one went to the Atlanteans to be hidden under the sea, and one went to Men, who buried it in a hole (come on, guys).
At the start of Justice League, Steppenwolf is on the hunt for the Mother Boxes now that Superman is dead. We see that the Atlantean and Amazonian Mother Boxes are still in their respective keeps, but Man’s Mother Box is in the possession of Cyborg’s father, S.T.A.R. Labs scientist Silas Stone. How’d it get there? Well in the epilogue to Wonder Woman, which was released online, we saw that Etta Candy (Lucy Davis) had assembled the remaining members of Steve and Diana’s World War I troupe for a new mission. She told them the following:
“This is our first mission, top secret. The war is over, but the good fight goes on. After the bombings in Liège along the western Belgian front, the powers that be found something. It’s very old. It’s very powerful. They want us to recover the artifact and deliver it to the Americans. I mean, we don’t want it in the wrong hands, do we?”
So, that’s how Man’s Mother Box got to America, and in Cyborg’s possession it serves as the final key for Steppenwolf to assemble Unity and begin his Earth takeover (again). By the end of the film, the Justice League has prevailed and the Mother Boxes have once again been disassembled. But where did they come from and what, exactly, do they do?
In the DC comics, the Mother Boxes were created by Apokoliptan scientist Himon, using a mysterious element called Element X. Apokalips is the planet where Darkseid, the biggest bad of the DC universe, rules, and Darkseid is hinted at as the one pulling the strings in all of this. Indeed, Steppenwolf wants to impress his alien nephew, which is one of the driving forces behind his attempt to rule Earth.