The truth comes out in “Tremors,” and not just Lena’s (Katie McGrath) feelings about Kara (Melissa Benoist) hiding her identity as Supergirl. As the two best friends go through a climactic conflict, J’onn (David Harewood) learns that his brother never reached the Phantom Zone while Alex (Chyler Leigh) and Kelly (Azie Tesfai) deal with the scars from their respective pasts.

Betrayed by the friend she betrayed.

“Tremors” also provides some background information on Leviathan, who are in their Supergirl iteration actually aliens who crash landed from the planet Jarhanpur and killed the dinosaurs in doing so. Since then, they’ve been keeping humanity in check from the shadows, presided over by their leader Rama Khan. I’m going to ignore that these names sound vaguely South Asian while all the Leviathan actors are thus far very much not, and instead point out that there’s a leadership conflict that revolves around… technology. Who said Supergirl wasn’t subtle?

Lena manages to turn Leviathan’s vendetta against her to her advantage, as she lures Rama Khan to her side at a public event after refusing to hand over the medallion. As onlookers all livestream the mysterious man’s face, Lena calls Supergirl for help and dives off a cliff into her arms. With this incentive, and Brainy (Jesse Rath) digging up information on the earth bender, Kara decides to take her best friend on a tour of the Fortress of Solitude to find which of Lex’s old toys can protect her. Which is precisely what Lena was gunning for, and which leads to the devastating confrontation at the climax of “Tremors.”

In fact, aside from the last few minutes of each storyline, this week’s episode of Supergirl was pretty lowkey. McGrath and Benoist knocked the reveal out of the park, and it was heartbreaking to see Kara’s worst fears about their relationship come true. Lena insists she’s not a villain, but the actions she’s taken up to now do more than blur lines. In “Tremors” she takes Myriad for herself and locks Kara up in the Fortress to cry herself to sleep with her own counterprogramming. That’s not villainous in and of itself, and her feelings of hurt and betrayal were certainly valid, but by doing so she exemplified the difference between pain inflicted accidentally versus intentionally.

We love their love!

Meanwhile, J’onn embraced his brother once more after M’yrnn (somehow?) came to inform him that Malefic was just across town. While the psychic connection and Malefic’s acceptance of it were both lovely to question, the efficiency of this plot was a weak point in “Tremors.” Did J’onn realize Lena was holding his brother captive, and if so why didn’t he inform Kara? Did Malefic really forgive his brother or is that the work of Lena’s control? Can he even tell J’onn about said control? As you can see, I spent what should have been a heartwarming moment instead running through all the questions Supergirl didn’t answer.

The last relationship confrontation was perhaps the most satisfying, as Alex finally acknowledged the pain Kelly was still in and how her own actions affected it. After yet another dangerous run-in, Alex was ready to get back to work without missing a beat. Kelly, however, was not so sure about. Though she dismissed her girlfriend’s concerns at first, Alex soon realized that Kelly was still healing from the death of her fiancee and had a hard time coping with the dangers. The sweet declaration to put each other first and continue healing together brought a tear to my eye. As a bonus, they even mentioned the unseen Nia calling after Brainy was injured in the same fight, so we can at least suppose Supergirl is letting them be happy for now – even if it’s inexplicably offscreen.

Supergirl airs Sundays at 9/8 on The CW.