Supergirl: Are there other Worldkillers?

Reign may not be alone in National City.

As revealed in a recent Supergirl episode, what viewers thought was the pod that brought Sam (Odette Annable) to Earth was actually more like a ship that seems to be housing others within. Though the show has gone a very different route from the comics, with Sam being a single mother unaware of her true heritage, fans of the comics know that her alter-ego Reign is one of a group of five bio-engineered weapons of Krypton. Could that ship therefore be housing other Worldkillers?

"I don't want to give away what that ship is and who is inside of it, because it's one of the big mysteries of the season," executive producer Andrew Kreisberg tells EW. "But you will find out who's in the ship very soon in episode 7."

Should the ship be filled with other Worldkillers, it could explain why Sam eventually suits up as Reign and turns against Kara (Melissa Benoist). Our theory: Discovering she was actually created as a weapon of Krypton will make Reign set her sights on the only Kryptonian left within reach: The Girl of Steel.

"I think you might be right," Benoist says of the theory.

"That's a great theory," Annable concurs. "You know, I'm going to go with yes, let's go with yes on that. I agree with you. You might be [onto something], but you might not be. I don't know, but I do know the story that we're going to share, and the reason why Reign happens and her motives are not to kill everyone. It's very specific and it's very pointed and it's all happening for a reason. Those reasons I don't know myself."

Alas, Kreisberg is quick to debunk that theory. "No, your theory is incorrect," the Supergirl boss says. "They ostensibly left at the same time, but there's a reason that Sam hasn't become Reign yet that will soon become apparent."

Supergirl airs Mondays at 8 p.m. ET on The CW.