A/N: Rewrite of 3x10. One-shot turned three-shot because of overwhelming tumblr response.

Overuse of the word 'friend' is dedicated to my Supergirl fandom partner-in-crime who doesn't ship endgame Supercorp, but is a really wonderful human being and still loves the chemistry between Melissa and Katie.

"S-sick," James manages to stammer. "With the flu. Bad flu. Flu bad. Really bad flu."

Lena stares at James for a beat. Then two.

Supergirl is hurt and missing.

Kara is mysterious friends with Supergirl.

James is the world's worst liar.

"When was the last time you talked to her?" Lena asks, hiding her suspicion far better than James hides his nervousness.

"Earlier today," he says, more smoothly than 'flu bad' but less smoothly than almost anything she's heard out of his mouth. "Called in sick. A little after you asked about her, in fact."

Kara hasn't texted her back in two days, one hour, and thirty four minutes. Lena highly doubts Kara would call in sick and not at least text her ask much as well. Or call her instead of James.

"Well. I should probably go check on her." Lena turns her back to James, who shouts with comical helplessness,

"No–aaaaaahhh I mean, no, but… but you don't want to get sick too!" James darts in front of Lena, holds his hands up like he's going to herd her back into the office. "We've got our hands full here. Let Kara rest up, and keep yourself well."

That was it. Something was wrong.

"James, one minute with my sick best friend isn't going to kill me." Lena pushes past him and out the door. James waits until she's out of earshot, and makes a panicked phone call.

"Winn? We're in trouble."

Lena marches up the stairs to Kara's apartment not fifteen minutes later. The deserted streets of National City made for record driving times.

Her manicured hand pounds on the door. "Kara? It's Lena!"

No answer. Lena bangs again.

"Kara, please answer the door." Lena tries not to think about all the pieces floating in her mind.

Kara is the only one who seems to be able to talk to Supergirl.

James has a history of being friends with Supers.

Kara hasn't texted her back in two days, one hour, and fifty-one minutes…

"Kara!" Lena shouts. There's a clatter inside, like someone hiting a window pane. Then heavy footsteps. Lena's heart races. What on earth…? "Kara?"

Latches click, and the door swings open. Kara, clad in bathrobe but otherwise appearing perfectly healthy, stands in the doorway. Lena feels the tightness in her chest relax.

Mostly.

"Kara," Lena breathes. "Thank god. I've been so worried. You didn't answer your phone for two days!"

"Yes. I– my phone. I was attempting to sleep off this sickness, so I have not used it in that time."

Alarm bells go off in Lena's head. "You haven't used it at all?"

"No." Kara's face is oddly serious. Yes, she seems sick… or just… not herself. "I have not. I am sorry for worrying you."

Lena's heart is racing. She could be entirely wrong. She's a Luthor. It's in her blood to be paranoid and suspicious. She could jeopardize their entire friendship with her doubt.

Lena takes a deep breath. Kara had her trust. And she had Kara's.

I will always believe in you.

"No, I'm sorry you're sick," Lena says in the most comforting voice she can. She steps forward quickly, arms raised for a hug. Kara holds her hands up with a meager "wait–" but before she can push Lena off, Lena's got both of Kara's wrists tight. She shoves them both into the apartment and kicks the door closed behind her.

Kara breaks free almost instantly, but the spell is already broken. "Who are you!?" Lena demands, swallowing her fear at… whatever it is. "Kara" stares her down, but does not answer.

"What have you done to Kara? Is she okay?" Lena is yelling again. "What… what does she have to do with Supergirl?"

'Kara' still stares at her, unflinching.

"Tell me!" Lena screams, pulling a handgun from her bag. 'Kara' stares from the gun to Lena's hard, scared eyes. There's no sign of aggression from the imposter. Lena feels like it's examining her as it stares into her eyes. Like it can read her mind.

"You will not shoot me," 'Kara' finally says. Lena shudders at Kara's voice.

"Please…" Lena lowers the gun. "Tell me what happened to my friend."

"Leave now, Lena Luthor."

"Tell me!"

Without warning, 'Kara' grabs her wrist, yanks the door open, and shoves Lena through before Lena has time to so much as raise the handgun.

"Kara!" Lena lunges at the door, but it slams in her face. She pounds on it and yells in frustration. "Tell me where Kara is!"

There's a clatter at the window again, and the room is silent.

Lena whips out her phone and dials, staring at the door all the while.

"James Olsen. Answers. Now."

Lena storms into the DEO office like a Fury. James Olsen trails behind her, embarrassed beyond belief. A pair of officers trail behind him, because somehow Lena convinced everyone to let her into the world's most secure government facility with just a couple of administrative escorts.

"Uhhhhhh," Winn articulates. "James. What did you do?"

James' already helpless face just grows more confused. He raises his hands in the universal I-don't-know-how-we-got-here-man-one-second-I-was-covering-for-Kara-and-the-next-Lena-hacked-into-the-DEO-mainframe-stole-the-address-and-made-us-drive-here gesture.

Lena marches right up to Winn, who has never been so intimidated by a woman in his life, and he works with Alex Danvers.

Behind the fury, behind the bravado and confidence, Lena Luthor is scared.

Supergirl is missing.

Kara is missing.

Kara is close to Supergirl.

Lena doesn't want these pieces to fit together. Not because she doesn't want her best friend to be Supergirl. Not because she's mad that Kara lied about it - though that was a can of worms they'd have to open someday.

Because –

Lena remembers the shaky phone camera footage. Supergirl, bleeding, beaten to a pulp. Supergirl, falling two hundred feet and making a crater in the concrete. Alex Danvers yelling for help. A team of military medics hoisting her limp body from the wreckage.

Suddenly she puts Kara's face on the broken body, and Lena can hardly breathe.

She stares down Winslow Schott - bless his geeky heart, he doesn't stand a chance here - with the fear and anger and raw love for her friend.

"Where. Is. Kara."