So, I was watching 'Last Refuge' and they made it pretty clear towards the end that Clarissa cannot remember her husband because they'd taken his younger (newborn) self long before she'd had the chance to meet him. It occurred to me that while all we get about Lisa is Len saying "she's a tough kid, she'll be fine", she would be in the same boat as Clarissa because her brother's younger self was removed from the timeline before she was even born. So I sat down, and this came out of that thought.

Note: I am calling bulls*** on some of the dates used in this episode. Specifically 1990 and 1993. If Mick saved Len in Juvie when Len was 14, then he was probably a little older and/or bigger than Len in order to intimidate or fight off the kids who were about to kill him. There's no way he was still that young (Young Rory's actor was born in 1999, so he's either 16 or 17) in 1990. Jax being born in 1993 has already been disproven by multiple mentions of the fact that he's not yet 21, and if he were born then, he'd be 22/23. 1972 as Snart's year of birth is questionable as well, because even if it's the exact birthdate of Snart's actor, Little Leo in 'Blood Ties' doesn't look young enough to be only three.

DISCLAIMER: I don't own Legends of Tomorrow or The Flash.

WORD COUNT: 1531

"Okay, so you're saying I was kidnapped by some time-travelling assassin to be used as leverage against you, but there's one problem with your insane story. Who the hell are you?"

Leonard Snart froze at the question, even if a part of him had already figured it out. Lisa, his baby sister, the girl he'd raised practically by himself, had been behaving coldly towards him since he and the others had found the Pilgrim's ship and escorted them onto the Waverider. A few questions had confirmed that she had been taken from 2016, just a few weeks after he'd left, but there was no grin on her face when she saw him, no calling him 'Lenny' or demanding to know why he hadn't called. She'd tensed up when he'd put his arm around her to guide her through the halls to the Med Bay, something that she would only do around strangers who dared to get too close without invitation. It was a trait they'd had in common. But the harshly-voiced question confirmed his fears.

"You don't remember me."

Raymond, who was nervously fussing over Anna on the other bed in the Med Bay, looked up. Taking the hint, he decided to escort his soon-to-be-dead fiancée out and give the Snart siblings some privacy.

Lisa scowled as the doors slid shut behind them. "Should I?"

He swallowed. "No, I guess not, but that's our fault, too. The assassin was after us, first, this team. So we grabbed our younger selves and hid them somewhere they would be safe. Little Me was kidnapped, or rescued, whatever you want to call it, as a newborn. So, naturally, that changed things. Changed them so that I wasn't there when you were born, or at any other point in your life."

She was still staring at him, but now there was a contemplative look in her eye. "My grandfather told me I had a brother. He was older than me, but my parents never got to take him home, because he went missing from the hospital. No one ever found out what happened to him. Was that…"

"Me? Yeah. I'm Leonard Snart, and I'm your older brother." He looked at her more closely, seeing a hardness in her that was both familiar and alien to him, because he was used to seeing it in his own reflection, but not in her. "How was it, growing up without me?"

Lisa frowned, narrowing her eyes at him. "Why do you care?"

"Because…" He slipped his left arm out of his jacket and rolled up the long sleeve of his shirt, displaying the scars. "I got this one stepping between you and Dad when you were ten. I got this…" He lifted the bottom of his shirt to reveal a long, red mark under his ribcage on his right side. "…for stopping him from taking a beer bottle to your head when you were eleven. I need to know what happened, what taking myself out of the equation did to you."

His sister stared at the scars, seemingly frozen in shock. Then she swallowed, and spoke. "There was no one to protect me when I was little. Mom took off after I was born, Grandpa only saw me when Dad was in prison." That much hadn't changed. "The first time he hit me, I was five." Five. Two years earlier than in the timeline he remembered. "And no one was there to stop him. By the time I was twelve, I'd had enough. I stole a knife from the kitchen, hid it in my room. The next time he came after me, I grabbed it and… I stabbed him. Right in the heart."

Leonard felt the breath leave his lungs. Twelve. His sister had been forced to kill at such a young age. Because he hadn't been there to protect her. "I'm sorry," he whispered, "You shouldn't have been put in that situation in the first place."

"So what? Is he still alive in your timeline?"

"No. When you were sixteen, he got busted for a botched armed robbery and went to prison, didn't get out for another ten years, at which point I stuck a gun in his face and told him to stay the hell out of our lives. And he did, until he broke out of prison in 2015, having gotten caught again, and decided to recruit me for a heist." Leonard allowed himself a smirk. "He never could admit that I was a smarter, better thief than he could ever hope to be. But of course I wasn't going to agree to join him, so he had to… persuade me. He… put a micro-bomb in your neck and told me if I disobeyed him, he'd detonate. You didn't even know it was there, but got worried when I went missing, enough that you went to some friends of the Flash for help – you know who the Flash is, right?"

"Goody-goody with super speed? Runs around catching criminals and other crazy powered people?"

"Yeah, him. He's the kind of fool who wants to save everyone, so once he and his pals found out about the bomb, they worked to get it out, and Flash himself even went undercover in our crew during the heist. Once he told me you were safe, I shot dear old Dad. Also right in the heart."

A heavy silence hung between them. Neither dared to break it for a long time. Leonard kept his gaze fixed to the Med Bay monitors as if they were the most interesting thing in the world, feeling Lisa's eyes burning holes in his back. Finally, he decided to speak up. "I'm sorry you grew up without anyone to look after you. I know what that's like. Mom leaving was the same; I met my partner Mick in Juvie, and until recently he's usually had my back, but it wasn't the same as having a protector. Making sure you were safe was the only thing that kept me going some days."

"I don't need your protection," she whispered, "As you can see, I've managed just fine on my own."

Leonard let out a short, humourless laugh. "You sound like me. Sara – the blonde – likes getting on my case about that. And for the record, in the old timeline, you're still tough as nails. I've spent a good chunk of life in prison, and nearly got murdered for the first time at age fourteen, so I know better than most that I won't live forever. I made sure you knew how to handle yourself, in case something ever happened to me."

Leonard heard Lisa slide off the bed, and turned around to see her approaching him cautiously. "I still don't remember you. But… I think I really would have liked having you around. You are going to fix this, right?"

"Yes. We'll do everything we can to get things back to normal. I promise." He gripped her shoulders, a gesture that came automatically, usually one that she took comfort in. When she tensed instead, he froze, forgetting that this wasn't a Lisa that was used to it. He pulled his hands away, murmuring an apology. Trying to escape the awkwardness of the situation, he picked up the little pill Rip had given him. "Uh… this can make you forget this whole thing. We've been screwing time up enough as it is, even if resetting things so that I'm back in your life may erase this whole incident. But for you, it's optional. Sara's dad and Raymond's fiancée will need to take them, because they've learned things they shouldn't about the future, but…"

"I want to remember." Lisa seemed just as surprised by her own words as he was, but after a moment to collect herself, she kept going. "I believe you, somehow, when you say you and your friends will do everything you can to put things back to normal, or at least what you remember as normal, but you can't promise you'll succeed. If… If you fail, then that means this will be the only time I get to know my brother. Please, please don't take that away from me."

Leonard swallowed, a lump forming in his throat. He suddenly realised that this could also be the last time he saw his baby sister. The amnesia pill was discarded in the nearest incinerator, and he pulled her into a hug. It was usually something reserved for when she was really upset, and after half a second he realised that this Lisa might not respond the same way. She did tense up again, at first, but to his surprise, she then shakily put her arms around him.

"You have always been the most important thing in my world, Lisa," he whispered, "I will do whatever it takes to come back to you."

I love the brother/sister dynamic between Len and Lisa. 'Nuff said.