When Man of Steel was released in 2013, there were a couple of Easter eggs that everybody spotted. In one of them, Kal-El boarded the Kryptonian scout ship and discovered four cryogenic pods, one of which was open. This has led many to speculate that the pod’s occupant was Kara Zor-El, better known as Superman's cousin Supergirl.

Of course, it was just an Easter egg that had led nowhere until now. But could that change sometime in the near future? According to recent rumors, this loose end will be tied up in the Man of Steel sequel.

Users on 4chan (where else?) speculate that Warner Bros. is secretly developing Man of Steel 2. They also say that Zack Snyder and Geoff Johns have already written the story, and the studio is searching for someone to write a script.

The biggest reveal says that Brainiac will be the main antagonist, and Supergirl will also make an appearance:

The sequel to Man of Steel has been developing in secret. Geoff Johns and Zack Snyder finished writing a story for the film back in November. Multiple writers were approached to turn it into a screenplay, including the writers from Watchmen and the 300 movie series. Brainiac will be the villain, and Supergirl will be introduced to the DCEU.

Fans have speculated for some time that Brainiac would be the main Man of Steel 2 antagonist. His arrival on Earth would be prompted by the same signal that brought Zod to Earth in Man of Steel. However, others recently speculated that Black Adam would appear in the sequel. So take what you will from it.

The seeds of Supergirl’s appearance were already planted. But the rumors could be based on the simple fact that Wonder Woman has proven to be a success with both critics and audiences.

Again, these are just rumors. But we'd certainly be glad if just half of them turned out to be true.