Lena Luthor has an endgame for her friendship with Kara Danvers.

In "Tremors," the next episode of Supergirl, Lena will confront Leviathan head-on in an attempt to fall under Kara's protection. Then, she hopes to end up at the Fortress of Solitude to get her hands on something for Project Non Nocere, her plan "to rid humanity of its instincts to hurt each other."

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The CBR-exclusive clip opens in Lena's apartment, while she sat on the couch reading. When her alarm chirped, she looked up and said, "You can come out now." At that, a Leviathan agent stepped into her living room, cocking a loaded gun and demanding, "Give me the medallion."

"I don't think so," Lena replied, only for the woman to fire a shot. However, it simply ricocheted off a force field. "I have the most intricate security system in the world," she explained. "I know all about Leviathan."

"No one knows all about Leviathan," the woman spat back. "Leviathan is unknowable."

"I'm not afraid," Lena declared, to which the woman replied, "You will be." With that, she disappeared into the shadows.

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When the woman left, Hope -- occupying Eve Teschmacher's body -- stepped forward. "She's gone," she confirmed. "I've reactivated heightened penthouse security. You were right as always, Ms. Luthor. Leviathan will attempt to retrieve the medallion at all costs, but why would you provoke them over something of no value?"

"It has value to me," Lena said. "The medallion was special to my mother. The fact that Leviathan wants it makes it useful. Lex theorized that Superman kept every weapon that was used against him in a special facility: the Fortress. Although he never found it, I think Lex was right. I think the perfect dispersal device for Project Non Nocere is hidden there, gathering dust, and Leviathan is going to help me find it."

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"Please don't underestimate the danger of Leviathan," Hope insisted. "You should cancel the L Corp event at the park. They will come after you."

"Let them come," Lena said with a sly smile. "Supergirl will save me."

Judging by photos from the upcoming episode, Lena does indeed make it up to the Fortress of Solitude with Kara. This may mean that she comes under fire at her big event, resulting in Kara sweeping her away and dropping her at the Fortress for safekeeping. Judging by the episode synopsis, which appears below, this will also lead Kara to discover Lena's true intentions.

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According to the episode description,

SOMETIMES THE PERSON YOU WOULD TAKE A BULLET FOR IS STANDING BEHIND THE TRIGGER – Supergirl (Melissa Benoist) finally learns the truth about Lena (Katie McGrath) while tangling with Leviathan. J’onn J’onnz (David Harewood) makes a discovery about his brother’s whereabouts. Andi Armaganian directed the episode written by J. Holtham & Katie Rose Rogers (#507). Original airdate 11/17/2019.

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.