Seeing what success Supergirl found with a flashback episode detailing the origin of the Danvers sisters’ bond, not to mention when they revealed what Lex was up to last year, it’s no surprise they tried again in “Confidence Women.” This time around, the relationship at its center was Lena (Katie McGrath) and Andrea (Julie Gonzalo), because a long time ago they used to be friends.

What even is Leviathan?

Jumping off the framing device of Andrea breaking into the DEO to kidnap/rescue her beloved Russell with the shadow powers we didn’t know she had, then turning to Lena for help, “Confidence Women” quickly dives into a 30 minute recap of the history between the two ladies. Bonding at boarding school over their absent families, Lena and Andrea became fast friends who shared all their secrets. One such secret was that Lena’s mother used to tell her stories of a mysterious Medallion of Acrata said to have magical powers, which is a shoutout out to Andrea’s comic book character.

What a lucky coincidence, then, that Andrea chose to devote her anthropological thesis to Aztec culture and could thus pinpoint the location of that exact medallion. I have to give Supergirl credit for letting Andrea be from Argentina, like her actress, and merely studying Aztec culture rather than pretending like she herself is a descendant. Either way, her research becomes invaluable to Lena when she needs the medallion to stop her brother Lex from killing Superman. Too bad her best friend betrays her at the last second and steals the medallion for herself – but not without a reasonable inducement.

“Confidence Women” seems to have the primary goal of making Andrea sympathetic, and it largely succeeds on that front. Her friendship with Lena was genuine and disinterested, and only her family’s failing business and father’s suicidal state led her to take the medallion of Acrata. Even then, she wouldn’t have done is unless that creepy old man from Leviathan hadn’t appeared and directly told her it would save her father’s life. While this doesn’t negate the pain Lena feels when she sees Andrea wearing the medallion – despite the plothole of Leviathan specifically warning her not to talk about it to anyone – it does explain Andrea’s behavior. Furthermore, Andrea wasn’t the one who captured Russell or brainwashed him into becoming Rip Roar; that was Leviathan’s doing once he got too close to discovering the truth. She went out of her way to save his life, and is trying to do so once more in the present, as long as Lena can help her.

A pretty awkward reunion.

In the meantime, Supergirl also devotes some time to rewriting Lena’s friendship with Kara (Melissa Benoist) to fit the current narrative. Now it turns out that Lena initially rejected Kara’s friendship overtures after being burned by Andrea – and forgive me if I say that it feels a little like a romantic story in which Lena and Andrea broke up before finding love again with Kara and Russell respectively. And while Leviathan took Lena and then Russell away from one, lies took Andrea and then Kara away from the other.

But now it’s Lena’s turn to be the liar. After an elaborate con that involves calling Kara in for a fake emergency and incepting the entire DEO so that Andrea can shadow power her way in and steal Rip Roar, Lena turns the tables and threatens Russell’s life to get the medallion back from Andrea. She’s already gone too far in previous episodes, but seeing her put a knife to his carotid artery really sealed the deal. The irony is that the medallion only activated powers that Andrea already had, so it may not be of any use to Lena. Also ironic? Andrea traded the medallion for Russell’s life only for Leviathan to shoot him as punishment for said trade. Who could help but feel sorry for her as she held her lover’s body and pleaded with this all-powerful entity?

Thankfully, “Confidence Women” wasn’t spent entirely on Lena and Andrea’s past. Supergirl reserved a few minutes for the rest of the cast, even showcasing the hypocrisy of Lena’s ‘Do No Harm’ plan when a possessed Brainy (Jesse Rath) tried to take Alex (Chyler Leigh) down to keep her from doing harm. J’onn (David Harewood) caught the first hint of Lena’s betrayal when he realized the psychic attack on the DEO had to come from his brother, and Kara caught a bigger fish while she questioned Russell. Not only was she able to inform William (Staz Nair) that his friend hadn’t turned traitor on purpose, she also learned the name Leviathan. A name Lena herself was also researching at the episode’s close.

Supergirl airs Sundays at 9/8c on The CW.