It started when you left the room for five minutes.

Five. Minutes.

You were only supposed to be on a quick work call—something remote, nothing too serious—but you needed silence. Which meant leaving your little sibling under the very watchful, very unpredictable care of Yelena.

You’d barely made it halfway down the hall when you heard giggling. Not the cautious kind either—full-bellied, chaotic, the kind your sibling only saved for moments of pure joy. Which was odd, considering who you’d left them with.

You came back to find Yelena Belova, elite assassin and world-class cynic, on the living room floor surrounded by mismatched LEGO bricks, letting your little sibling decorate her combat boots with stickers and sparkly pipe cleaners like she was some kind of post-apocalyptic art project.

“What?” she deadpanned, not even bothering to stop them. “You said to babysit. I’m babysitting. They said my boots looked boring.”

Your sibling beamed, holding up a pink glitter sticker. “She said if anyone tries to mess with me, she’ll throw a knife at their face.”

Yelena offered a tiny shrug. “It’s true.”

You gave her a look. She rolled her eyes.

“Fine. I told them metaphorically I would throw a knife. Happy?”

Still, your sibling had crawled right into her space without hesitation, and Yelena—stoic, lethal Yelena—had let them. No flinch, no sharp edge. Just quiet attention, a few sarcastic quips, and a kind of fierce protectiveness you’d seen before, but rarely like this.

Later, as your sibling napped on the couch, their head resting against Yelena’s shoulder, she didn’t move.

“I like them,” she said softly. “They’re loud. And weird. Like you.”