SPOILER WARNING: This article contains major spoilers for "Tremors," the latest episode of Supergirl.
Supergirl just unraveled the mystery of Leviathan. "Tremors," the latest episode, showed the shady organization and its leaders for the first time on the series to date. As it turns out, the group is run by ancient aliens who made it their mission to protect the planet from its greatest threat: humanity.
When Margot failed to retrieve the Acrata medallion from Lena Luthor, she returned empty-handed to Levithan's leader, Rama Khan. In response, he lectured her about his history and purpose, saying, "Do you know how long that I've been safeguarding this planet? Since our ship, as big as an asteroid, wiped out the dinosaurs. Then humanity rose and became a scourge to this planet. For eons, we have kept their destructive behavior at bay, but now they're ravaging the Earth like never before."
At one point, his associate Gamemnae interjected and dismissed Margot. "You and I both share the same goal of want to put a stop to people who disrespect this planet," she told him. She insisted that they focus on using technology against humanity instead of brute force.
"Oh, the rising of oceans and raging of rivers will always work," he replied. "Our elder left the caretaking of this planet to me for a reason."
Following this discussion, Rama Khan attacked Lena at a press event. Supergirl rescued her, but not before the press in attendance snapped a few photos of him. This allowed the D.E.O. to track him down, which led them to discover how ancient he truly is -- and how he is connected to many "natural" disasters.
"Several reliable sources place this man at the scene of the crime throughout history: Pompeii, the Yellow River Flood of 1887, the Bhola Cyclone, even as far back as Noah's flood," Brainiac-5 explained as he debriefed Kara, Alex and Lena.
Later, at the Fortress of Solitude, Kara and Lena were able to point exactly where Rama Khan is from. "The only alien matching that description comes from a sister planet of Krypton, Jarhanpur," the supercomputer revealed. "The planet was destroyed after years of civil war, but five of its leaders fled. One of those leaders has the extraordinary power to bend the Earth to his will."
Eventually, Rama Khan was able to locate both Supergirl and Lena at the Fortress. Rama Khan fought the Girl of Steel but, because he was on a piece of Krypton, his Earth-bending powers didn't work. With some help from Lena, she was able to subdue him, but it appears he isn't gone for good. The synopsis for next week's episode, the aptly titled "The Wrath of Rama Khan," promises another face off with the ancient alien.
What's more, Brainy learned that Leviathan's headquarters is actually based in National City. After discovering a connection between Rama Khan and a specific symbol, he tracked down their lair. However, the organization has technology so advanced it was able to prevent even Brainy from accessing their true seat of power.
Both Rama Khan and Gamemnae appear in the comics. Rama Khan debuted in 2002's JLA #62 by Joe Kelly and Doug Mahnke as the leader of a nation called Jarhanpur, which existed around 1,000 BC. He eventually traveled to Atlantis, where he ruled alongside Gamemnae, who first appeared in 2002's JLA #70 by Joe Kelly and Doug Mahnke. Gamemnae, a powerful sorceress, is native to Atlantis. She eventually absorbed his essence to gain his powers, and his name was passed down like a title until the 21st century. They both fought the Justice League. Judging by the fact that Supergirl introduced them as aliens, the show is likely retooling and updating their origin for a new purpose.
Airing Sundays at 9 p.m. ET/PT on The CW, Supergirl stars Melissa Benoist as Kara Danvers, David Harewood as Martian Manhunter, Mehcad Brooks as Jimmy Olsen and Chyler Leigh as Alex Danvers.