Author's Note: I've been rewatching Supergirl to get details for a different project. Got to this episode, and of course my little shipper mind immediately went "Replace Mon-El with Lena!" So...

Disclaimer: Any recognizable dialogue from the episode belongs to the creative team over at DC/CW.

Duet Redux

Lena Luthor can tell something is wrong as soon as the call connects.

"Hi Lena." Kara's voice sounds thick, her tone clearly unhappy. Is she crying?

"What's wrong?"

She hears a sniffle on the other end of the line. "I… it's nothing. What-"

"Bullshit." Lena hears a small noise from Kara, a squeak or a chuckle that is definitely mixed with a sob. "Where are you?"

"My place."

"I'm on my way."

Barely fifteen minutes later, Lena knocks on the door of apartment 4A. Thankfully, Kara opens it almost immediately. Lena takes a moment to study her friend, noting the usual neat clothes (Only Kara can make pink and white horizontal stripes look that good.) and pulled-back blonde locks. Then she catches sight of Kara's eyes, red-rimmed and teary, and with barely a second thought Lena reaches out to enfold Kara in a hug. Kara doesn't protest, simply wraps her arms around Lena in return and buries her face in the smaller woman's neck.

They stay like that for several long moments before Lena remembers that they're still standing in the doorway of the apartment. She gently rubs her hand up and down Kara's back. "Can I come in?"

"Oh!" Kara pulls back, chuckling, the sound signaling a step back towards normal. "Sorry, yeah." She steps aside, wiping at her eyes. Lena suddenly realizes Kara isn't wearing her glasses. Such blue eyes…

Shaking herself, Lena walks inside. "Care to tell me what's going on?" she asks as she sets her purse down on the dining room table. She pulls off her coat as she turns back to her friend. "And don't try to tell me it's nothing." Kara ducks her head, the back of her neck flushing as she closes the door and mumbles something. Lena fights a smirk at the very Kara action. "What was that?"

Kara turns away from the door, but her eyes won't leave her feet. "I broke up with Mike."

It takes Lena a moment to figure out how to respond. She never really liked Mike; he'd always been a bit too full of himself, too ready to push his way into any conversation or gathering as if he had a right to be there. (The memory of how he basically invited himself to Lena's gala still makes her angry.) At first, Kara had seemed to share that opinion, ranting to Lena whenever the overgrown frat boy did something stupid. But Kara is Kara, and gave the man way too many chances, and at some point her stories about him changed to how he was working so hard, how he seemed to finally be growing up. While Lena hadn't been pleased to learn the pair were dating, she had liked seeing how happy Kara was. Which begs the question… "Why?"

Kara starts fidgeting with the hem of her shirt. "I… I found out he lied to me. About who he is."

That must have been a hell of a lie, Lena thinks. Maybe she can ask… Later. Comfort Kara now. "Kara. Hey, look at me." Reluctantly, the blonde does. Lena notes that she seems more embarrassed than outright upset now; at least the tears have stopped. "It's okay to be upset. Trust me, I know how it feels to be lied to."

Kara blushes. "It sucks."

"It does," Lena agrees. "Now," she walks over to her friend and grabs the blonde's hand, "what would you like to do? Do you want to be by yourself for a bit?" Kara shakes her head emphatically. "Alright, do you want to talk? Watch a movie? How can I help?"

Kara tilts her head slightly, looking at her with those amazing eyes and Lena has the oddest sense of déjà vu. She looks like… "Could we-" A knock on the door cuts her off. Lena jumps at the sudden noise, dropping Kara's hand. For her part, the blonde turns back to the door, looking at it as if trying to see who's on the other side. A moment later, she reaches for the knob, opening the door slightly. "Can I help you?"

"Here you are!" A dark-haired man pushes his way into the apartment. His eyes lock on Lena, and he grins. "Oh good! You're here too!"

"Excuse me?" Lena doesn't recognize him, but he certainly acts like he knows her. "Who the hell are you?"

"Oh that's not important." He waves his hands as he breezes by, heading for the kitchen area.

"Hey!" Kara appears in front of Lena, snatching the man's arm to bring him to a halt. "You can't just come in here-"

"But I just did!" The man turns in Kara's grasp, his smile widening. "I've been looking for you." Something in his tone sets Lena's teeth on edge. Then his eyes start… flashing? Is that the right word? Rings of purple and silver radiate out from his pupils. He's not even looking at Lena and she feels a little lightheaded. Kara drops his arm and starts swaying on the spot. "Now then," he turns, rubbing his hands together as he studies the apartment, "where is… Aha!" He darts forward, snatching something off the counter. "Just what I need!" He looks back at Lena, still grinning. "Want to see a trick?" He holds up the thing he picked up, a circular, silver device with a glowing blue center. "Abracadabra!" He thumbs the device's center. Light erupts behind him, a circle of cascading blue and white that looks like water but hangs in midair. What the hell?

The man speaks again, his tone that of a stage entertainer. "Ladies, this dimension has been so much fun. I've had a blast but I've gotta go chase down the fastest man alive. Toodles!" He drops the device and jumps backwards into the light, which flares briefly before disappearing all together. Before Lena can even start to process what's just happened, Kara collapses.

"Kara!" Lena tries to catch her friend, but only manages to lower her gently to the ground. How does she weigh that much? Lena shakes her head; there are more immediate problems. She quickly checks Kara's pulse and breathing before digging in the blonde's pocket for her cell phone. Thankfully, the emergency contact doesn't require a password. Lena smooths Kara's hair back as the phone rings once, twice.

"What's up, Kara?"

"Alex, this is Lena Luthor. Something's happened to Kara."

Barry Allen refuses to say it out loud, but he's kind of glad that HR texted him. Watching musicals on Cisco's couch hasn't been as comforting as it normally is, so maybe a good supervillain chase will help pull him out of his funk. It's your own fault you know…

Thankfully, HR's voice derails that train of thought. "BA? Someone's comin' through."

Looking up, Barry realizes that, yes, there is an active portal in the lab.

"Could be Gypsy," Cisco says hopefully.

"Yeah," HR says, although from his tone he doesn't think so, "or it could be…"

A group of three people appear as the breach collapses. Barry recognizes J'onn J'onzz from Kara's description, but the other guy is a mystery. However, unconscious in Mystery Guy's arms … "Kara." Barry looks at the two men. "What happened to her?"

"We don't know," J'onn replies. "But whoever did it has come to this world."

Crap.

..

Looking at Kara lying unmoving on a bed in the S.T.A.R. Labs infirmary has to be one of Barry's least favorite sights. He can't decide if it's better or worse that she's wearing regular clothes and not her Supergirl suit. Iris enters the room, gives Barry a nod as she comes to a halt by the foot of the bed.

"Her vitals are low," Caitlin notes as she finishes hooking up the monitors. "How long has she been like this?"

"A few hours," J'onn replies. At first glance, he appears calm, but a closer reveals tense muscles that betray his worry.

"Okay," Mystery Guy says, arms folded as he stands next to the bed, "we need to find whoever did this to Kara and punch him repeatedly until he reverses whatever spell he put on her, and I get to punch him first."

His attitude doesn't sit right with Barry. "Who are you exactly?"

The guy finally looks up from Kara's prone form. "My name's Mon-El. I'm Kara's… friend." At Barry's look, he continues, "We're more… more than friends." A pause. "We've been kissing a lot."

"Oh." Caitlin sounds as surprised as Barry feels. "She never mentioned she had a boyfriend."

"It's a recent thing," Mon-El explains.

J'onn gives him a hard look. "Didn't you two just break up?"

Mon-El looks ready to argue the point. Thankfully, Iris speaks up first. "So what happened, exactly?"

Mon-El subsides and goes back to looking gloomily at Kara. J'onn turns his attention to Iris. "From what I understand, Kara was at her apartment with a friend when there was a knock on the door. Kara opened the door, and a man pushed his way inside. He somehow hypnotized Kara, found the breach device you gave her, and used it to disappear. Kara passed out when he vanished. Kara's friend called Alex. Alex and I brought Kara to the DEO, but we couldn't wake her up. Another agent tracked the man that did this to this Earth, so we decided to bring her here."

"Okay, but why this Earth?" Iris asks.

"We believe," J'onn turns his attention to Barry, "he's looking for you."

"What? Why, why do you think that?"

"Because," Mon-El looks up at Barry, "before he disappeared, he apparently mentioned coming to find the fastest man alive."

Well, I wanted a supervillain chase… Barry sighs. "Come on." He motions for J'onn and Mon-El to follow him, unsurprised when Cisco follows. "Do you have any idea where this guy came from?" he asks as he leads them to the main lab area. If they have something that can be entered into the computers…

Sadly, that hope is quickly dashed. "No," J'onn replies. "Kara's building isn't exactly Fort Knox."

"Uh, guys?" Cisco stares at one of the monitors. "Some dude just literally appeared out of nowhere down in the speed lab."

Barry, J'onn, and Mon-El hurry over to look. "He matches the description Lena gave," Mon-El notes.

That's all Barry needs to hear. "I'll take care of this." He switches over to superspeed, grabbing his suit and blasting out of the lab, swerving at the last minute to avoid HR and Wally in the hallway.

When Barry arrives at the speed lab, Mystery Guy 2 is sitting with his feet up on one of the consoles. "Hello, Barry Allen."

Slowly, Barry moves towards the guy, noting his appearance (dark hair and eyes, business-casual attire) and relaxed posture. "How do you-"

"Know your name?" MG2 scoffs. "I know a lot of things. And I can do a lot of things, too." A sizzling sound pulls Barry's attention back to the door as Wally, fully suited up, skids in. "Whoa! Wally West made it here, too! This is exciting!" Barry shoots Wally a questioning look, but Wally only gives him a slight nod in reply. "Good of you to join the party, Kid Flash. I'm happy to have you." Oddly, MG2 sounds like he means it.

"What do you want with Supergirl?" Wally demands.

Barry turns his attention back to their guest as the man replies, "The same thing I want with both of you: To teach you all a lesson."

Barry barely has time to think, That can't be good, before MG2 literally speeds out of his chair and collides with Wally, sending the young man into the wall. Wally grunts as he hits the floor.

"Is that all you got, Kid Flash?" the uninvited guest taunts as Wally scrambles upright. "I mean, you look a little scared."

Barry speeds up behind the man, planning to take him by surprise while his focus is elsewhere. Instead, Barry is surprised when the man turns around and stops him with a hand to the throat. "And you're too slow." MG2 lifts Barry by the neck and slams him into the ground. "Nighty-night, Flash," he says as rings of purple and silver begin to flash in his eyes.

Barry can't gather his thoughts. His eyes are getting heavy. What's happ—He blacks out before he can even finish the thought.

Author's Note: Look for updates on Saturdays!