SPOILER WARNING: This article contains major spoilers for "The Darkest Place," the latest episode of "Supergirl."

Superman may not be the only Justice League member to exist on "Supergirl's" world. In "The Darkest Place," the latest episode of "Supergirl," Kara dropped a reference that suggests that Batman exists on her world.

The episode's opening scene found Kara hanging out with Alex, James and Winn at Maggie's favorite alien dive bar. As they sat around a table, sipping on their drinks, they discussed the emergence of Guardian, National City's newest vigilante. Of course, James and Winn know more about Guardian than they let on, seeing as James is Guardian and Winn is what Alex dubs "Guardian's sidekick" -- but they're the only ones in the know when the episode kicks off.

During their conversation, Kara makes it very clear that she isn't Guardian's biggest fan. After all, her cousin -- Superman! -- once worked with a vigilante, who she called "crazy." She adds that this aforementioned vigilante also tends to use a lot of gadgets. Considering the context of the discussion, it sounds as if this vigilante doesn't have superpowers either.

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If that sounds familiar, that's because gadgets are Batman's go-to. It's far from a direct confirmation, but -- in addition to the Gotham namedrop in Season 2's premiere episode -- it seems very likely that the writers are referencing the one and only Dark Knight, the other half of the World's Finest.

Of course, while it seems incredibly likely that Kara was talking about Batman, this could reference other DC Comics characters as well. Take, for instance, Green Arrow. As fans of the "Arrow"-verse are aware, Green Arrow is a vigilante who uses trick arrows and skill in place of superpowers. Nevertheless, Superman is most frequently paired with Batman, so chances are strong that the reference was intended to hint at the Dark Knight.

Starring Melissa Benoist as the Girl of Steel, "Supergirl" airs Mondays at 8 pm ET/PT on The CW. The series also stars David Harewood as Martian Manhunter, Mehcad Brooks as Jimmy Olsen, Chyler Leigh as Alex Danvers and Jeremy Jordan as Winn Schott and features appearances by Calista Flockhart's Cat Grant as well as Tyler Hoechlin's Superman.