She's in a room with everybody she cares about, and two people she knows will grow to be important to her ; yet, Lena feels like she merely exists next to them. Kara is glaring at Sam who's staring at Alex who's clenching Kelly's hand and gazing at Ruby who's looking at Lena like she's her anchor in this situation. Lena doesn't dare telling her that she might not be the sanest person to rest upon.

Lena is looking at Kelly who dutifully sits at Alex's sides. She brought tea and biscuits for everyone, and even mastered Ruby's hot chocolate on the first try ; but now that there isn't much to do anymore, she looks like she doesn't know what to do with herself. And Lena understands. Because if she herself feels out of place here, even as moral support for both Sam and Kara, it must be a thousand times worse for the woman who has to deal with her fiancée's ex and daughter at the same time.

"Okay," Ruby says suddenly, shoving her hot chocolate mug on the coffee table and straightening up to her full twelve years old height. "Aunt Lena, you're the least crazy person here, tell me what's going on. I don't understand what I'm doing here or why red hair person is looking at me like I hold the answer to the universe. Which is 42 by the way so red hair person, Alex ? Can you please stop staring at me ?"

"Sorry kid," Alex mutters averting her eyes to look at her knees instead. "Didn't mean to freak you out."

"Do I know you ?" Ruby asks shyly after a stretch of silence long enough for her false bravado to falter. "Because I feel like I do and I seriously don't understand."

"I've made a mistake," Sam whispers. "I'm sorry."

"Are you serious ?!" Kara shouts, jumping out of her seat and stopping her death course towards Sam only because Lena manages to grab her hand at the last second. "Are you serious ?"

"I didn't mean know," Sam says, "and I was talking to Ruby." She stops, her eyes flickering everywhere across the room as she tries to swallow the rock blocking the words in her throat. "Ruby," she says, turning to her daughter, "ten years ago, I've made a very big mistake. I hope you can forgive me. If you can't, that's okay, I'll love you all the same."

Her eyes briefly leave Ruby for a second, and she turns to Lena in a silent plea. Lena shuffles closer to the edge of the couch, and, still keeping one hand firmly around Kara's, she reaches out to put her free one on Sam's knee. They share a small smile, a sad heart broken one, but she does her best to give her all of her courage.

"If you feel like you know Alex, it's because you do." Sam forces herself to look at Ruby. It pains her, everybody can see that, but Lena knows her best friend, knows her strength, and so she knows she'll pull through, no matter the cost. "I loved her once," she says, her voice wavering but not breaking. "Love her still. And she's your mum."

A beat passes, two, during which Lena notices Alex consciously not looking at Ruby and Kara consciously not crushing her hand. She waits, they're all waiting for something to happen ; either for Ruby to say something or for Sam to keep talking, but neither of these things happen. Instead, Alex is the one who finds the courage to speak. "I want you to know," she says with great difficulty, "that I looked for you. I would have never abandoned you, and I kept searching for a long time. You're Sam's, but I love you like my own." She's overflowing with words, thoughts, and not speaking seems as hard as doing so. Ruby looks at her, and she looks at Ruby, and Lena's heart aches for everyone in this room.

In the time it takes for Ruby to find words to say, Kara has sat back down beside Lena and Sam is gripping her hand with a bit too much pressure for it to be comfortable. Time seems suspended yet everything rushes forward and in the second before it crashes down, Lena thinks she understand at least some part of what Kara said about entropy. The universe doesn't care if it destroys lives.

"Why ?" Ruby croaks this single word and it's a word that everybody was probably expecting, still, it hurts. It hurts in its all encompassing simplicity, and its childlike misunderstanding. It hurts because it's the only thing anyone could possibly think about asking in this situation, yet it's the one question no one wants a full answer to. Ruby asks, but her eyes tell everyone that the answer might no be welcomed. Lena remembers asking this exact question, this life altering, universe shattering question to her father on his death bed when he told her she was indeed his daughter. Why ? Ruby asks it again ; "why ?"

There is a moment during which Lena thinks that she was wrong, that Sam is going to crumble, that she wont be able to push through and answer. But she does, she goes to open her mouth, her brain working double time to craft words. "I found out some things, about us." She says it slowly, painfully. "And we had to leave."

"Is it because we're..." Ruby tries, letting the end of her sentence trail into nothingness.

"No Rubes," Sam sighs, "it's not because we're aliens. Well not entirely. Kara is like us. Same planet. And she's your godmother."

"If she's like us, then why did we leave ? The two of you are invincible, you could have protected us from anything."

"From anything," Sam sighs defeatedly, "but not from myself."

"For Rao's sake, can you stop being so vague," Kara spits, tensed beside Lena. "Your kid needs answers, we all need answers !" Lena can feel angry heat radiating from her in waves. Her taut muscles could rip her apart in seconds, but she doesn't let this scare her. Instead, she rubs the pad of her thumb on her skin, over and over again, giving Kara something to focus on.

"When you were almost two, you broke Alex's hand," Sam continues.

"It's alright kiddo," Alex says softly, "it was an accident."

Ruby looks up from her much too powerful hands to lay her eyes on Alex, and she smiles, truly smiles at her for what Lena suspects is the first time in ten years.

"We'd been happy, blissfully so, the three of us living together, but when I realised my genetic had overridden your father's, I started looking for answers. I wanted to know as much as I could about Krypton so that when the moment came I'd be able to teach you everything."

"You could have asked me," Kara says faintly, maybe more to herself than really to Sam.

"But you didn't know everything," Sam replies with an aching smile. "I know now that I should have just talked to you but at that time, I wanted to do just one thing by myself. Because I was raising a toddler with the love of my life but we were barely twenty. Barely twenty. Exhausted from college and from raising Ruby and we needed help from everyone and I wanted to do one thing, just one thing on my own."

"I would have helped," Alex whispers, "you know that."

Sam ignores her, it's painful for her to do so, and maybe a bit rude, but Lena knows her friend, and knows she needs to keep going. "I guilt tripped Kal into helping me. Thanks to him, I was able to access every archive on Krypton, as well as the Lanterns' records on our space sector. Only two ships left Krypton when it exploded."

"But there are three of us," Kara says, disbelief and confusion etched on her face.

"I crossed referenced this with records on my family. They weren't just working on the Black Mercy." Her words are swallowed by the tightness of her throat and she has to stop talking for long seconds. She stares at Kara, trying to communicate something, something heavy and game changing that Lena doesn't understand. "They tried to revive Project Worldkiller."

"How…?"

"Let me finish," Sam pleads, "please Kara. Let me finish and then you can ask all the questions you want. Everybody can ask me anything but I just need to say this."

Kara's world, her beliefs, are on the verge of exploding a second time, and if they do, Lena doesn't know if she's going to be able to help, if she'll manage to hold her together. She feels her tense even further, like she's about to burst, but all she says is : "okay. Okay. I'm sorry, I'm listening."

"It couldn't be you," Sam says, barely over a whisper, "because you remember Krypton. And it couldn't be Kal, because you remember him. So that left only me. I thought I was a Worldkiller."

Lena realises that what Sam just dropped is a nuclear bomb, but what it means for Kara, for Kryptonians, she doesn't understand. The word itself is self explanatory, worldkiller, it sends chills down her spine, but Kara herself seems to have been turned to ice.

"There are no records of my birth and since Worldkillers are genetically bioengineered, it made sense to me. Since Ruby's birth, I'd been having a lot of nightmares, and if there was the slightest chance I could be awakening, I had to get away from all of you. Worldkillers are much stronger than Kryptonians, and I would have killed you Kara. I don't even want to think about what I could have done to you Alex. I thought about leaving Ruby with you, I wanted to, it was the best way to protect her. You were a fantastic mum to her and Kara could have taught her everything about Krypton. But it was like trying to rip a piece of me. So I took her with me, stole heart cloaking devices from Kal and changed our last name."

"And you left," Alex concludes for her.

"I left."

"Are you," a little voice chimes in hesitantly, "are you a Worldkiller Mum ?"

"I don't know Rubes," Sam whispers. "I don't know."

"You don't know ?" Kara asks, her voice wavering with poorly restrained fear and anger. "You drop something like that, and you don't know ? You leave us for ten years, and you don't know ? You come back, and you don't fucking know ?!"

"I'm sorry Kara."

"Sorry isn't fucking enough."

"After I met Lena, I started thinking about it the scientific way," Sam says in a rush, fully conscious that Kara could kill her here and now. It downs on Lena, maybe harder than any other time when she's been confronted to Kara's alienness, that her girlfriend is not from this world, she's closer to a god than anything, and the power she wields and restrains could destroy them all. "I tested myself," Sam continues, "tinkered with my body basically. I was looking for a trigger, something that I could block that would make sure I wouldn't lose it. Meanwhile I was losing it in a completely different manner. I missed you like crazy, and Ruby missed you too. I wanted to come back, but I also wanted to be sure I wasn't dangerous and so I kept looking and experimenting until I realised I had no way to know for sure, and by then it was too late. Ruby had long stopped calling after you and you were engaged to a cop. I didn't think there was a place in your life for me anymore."

"There would have been," Alex whispers, "I would have made space for you and for Ruby." Her small and broken voice snaps Kara out of her angry daze, and beside her, Lena feels all the fight drain out of her. She sags in the couch, suddenly out of place in the way her body tries to contain her pain. "And I'll make space for you now," Alex continues, "if that's okay with you Ruby. You don't have to answer now, you can think about it. And you don't have to call me mum. I just want a chance to get to know you."

"You lied to me," Ruby says as harshly as a kid can. "You lied to me," she repeats, barely looking at her mother. "When I asked why you were crying on every single one of my birthday. When I asked why I only had one parent. When I..."

"I told you the truth about your father," Sam says weakly.

"I don't care about Peter !" Ruby explodes, rising from where she's sitting next to her mother. She's floating a few inches off the ground, her fists tight and trembling. "He didn't want me ! But she did ! I don't care if you're dangerous, if you're a worldkilling person, you're my Yeyu and I love you. But you could have told me the truth. You could have told me why half of my baby pictures are missing. Maybe I'd have known it was Alex's face in my dreams and maybe I would have stopped missing someone I didn't even remember. You could have just told me Yeyu."

Sam slowly shakes her head. "You wouldn't have understood," she says, "you were so young."

"Well I understand it even less now." The ground shakes when her feet hit it, the floorboards creaking in a worrying way. She goes to leave, shaking Sam's hand off when she tries to catch her, and almost rips the door on her uncontrolled way out.

Lena is just starting to think of a way to stop a kryptonian teenager from running away when Kara disappears from her side and catches up with Ruby in a blur. "Come on kid, I'll buy you ice cream."

There's a beat, a frightening silence during which the whole room holds its breath waiting for Ruby to snap ; it doesn't happen. "Can we get donuts too ?"

"Sure thing," Kara says, shrugging on her thick tan jacket. Before they leave, she glances back at them with a small sad smile, and in her eyes is the assurance that beyond her hatred of Sam, she'll take care of her goddaughter no matter what.

"I just got off the phone with Sam," Lena says as she emerges on the roof, "I don't know what you said to Ruby, but she came home and went straight to sleep on the couch, cuddled up to her."

It's been a long tedious day, and she's exhausted. Every single part of her body screams for her to go lie down and sleep for the next twelve hours, but she catches a glimpse of Kara's golden hair, and pushes through.

"That's the way this kid is," Kara replies, patting the concrete beside her for Lena to sit. "She used to do the same thing when she was a baby. She'd get upset, crawl out of the room and refuse to come back until someone came and listened to her babble nonsense for a couple of minutes. She just needed someone to be there while she made sense of the mess in her head."

"Do you need someone to sit with you while you make sense of the mess in your head ?" Lena asks softly, padding closer until she reaches her usual sitting spot. Kara looks tired too. Less so than Lena thanks to her alien biology, but there still are shadows under her eyes, and a hardness in her jaw that wasn't there before.

"I'm fi…" she starts, before meeting Lena's soft glare and cutting her lie short. "I'm not even remotely fine."

"That's completely legitimate."

"But I wouldn't even know where to start unpacking all of this." Kara sighs, her breath full of confusion, unsaid words, and ice crystals. Tiny snowflakes float to Lena and she catches them in her hands, watching them melt as Kara takes the time to think. "Did Sam ever told you about the Worldkillers ?"

"No," Lena replies softly, "she never did. I knew she broke up with Alex for a reason, and that she was struggling with something, but she never gave me the specifics. If she had, I might have been able to help."

"Can I tell you about them ?" Kara asks hesitantly. "It's not a nice story."

"You can tell me about anything you want. Really."

Kara opens her mouth, stammers, hesitates, then screws her eyes shut before opening them again with a new sharpness in her gaze. "Unlike most children on Krypton, I didn't grew up thinking the Worldkillers were a myth. My father was a scientist and he was very real about this with me. To him, the Worldkillers weren't just a thing you'd talk about to get your kids to eat diner, they were a very real part of Krypton's history, one that shouldn't be hidden. I was still terrified of them." She chuckles, and sighs, shooting a sad tenuous smile that twists Lena's guts. "Project Worldkiller happened a few hundred cycles before my birth. It was a terraforming, well kryptonforming I guess, project that was supposed to help Krypton colonise nearby planets, at their expense of course. Krypton had a very high gravity and getting out of its pull was hard. Worldkillers were bioengineered to be stronger than regular Kryptonians so they could endure just about anything, including getting out of the planet's atmosphere. They were also encoded with a strong moral code and attachment to their home planet so that when faced with extreme circumstances, they'd always chose Krypton's side. Admittedly, it was a terrible idea."

"That's a mild way to say it."

"At the time," Kara says, acknowledging Lena's remark with a short laugh, "Kryptonians hadn't fully master accelerated growth, so the Worldkillers had to be raised in a lab. Before they were fully grown, someone altered their genetic code and set them loose on Argo City. There were hundreds of deads. Now, legend has it that a mighty heir of the House of El, assisted by Flamebird and Nightwing, rose to the occasion and defeated all five Worldkillers. Truth is he nuked part of Argo City and only got four of them. A sixth Worldkiller, with a built in trigger, had to be raised to hunt down the remaining one. It took seven years, and Krypton never attempted to colonise anything ever again."

"That's," Lena starts, trying to find a word to summarise what she's feeling right now. "That's terrible."

"It doesn't stop here. There'd been so much death and destruction, and the last Worldkiller had been such a helpful killing machine, that the Voice of Rao, Krypton's religious leader at the time, decided to spare their life." Kara snarls in distaste, her features distorting in an almost ugly expression. "The trigger was switched off, the Worldkiller made Kryptonian and integrated in society. Until one day they snapped, and killed sixty people, including thirty seven kids."

Kara swallows harshly, and lets the silence stretch after her words. She's hunched over, deflated, and when Lena reaches out to take her hand, she shivers. A question hangs in the air, and Kara doesn't seem ready to broach it, but Lena has to ask. She has to, because if she doesn't, she doesn't know where her brain could take her. "Do you think Sam…?"

"I don't know," Kara sighs. "From the outside, you can't tell the difference between a Kryptonian and a Worldkiller. We'd have to run tests. Do the thing we would have done years ago if she'd just told me, if she'd let me help. I wish I'd thought about the heart cloaking devices. Or that I had another idea to track her. It would have saved Alex the heartbreak. And Sam a decade of worrying."

"It's not your fault."

"I know," Kara replies with a smile, turning slightly to look at Lena. Warmth is starting to return to her eyes, and they twinkle when she brings Lena's hand to her mouth. "I still wish I'd done things differently, tried harder," she says, "but I know it's not my fault. And I do feel better know that I've shared this with you."

"I'm glad I could help," Lena says. She wiggles closer, and leans in until she can lay a soft kiss on the corner of Kara's mouth. Before she has time to fully do so, Kara turns and captures her lips with hers. They kiss lazily, their mouths sliding against each other unhurriedly. The last rays of sun warm her back, and it's almost relaxing. Almost, because when Lena closes her eyes, she can't help but superimpose Sam's face on the masked body of the out of control vigilante.