The house seals itself with a sound like bone settling into place.

Not a slam. Not dramatic. Just final.

You feel it through the floorboards before Sirius reacts, old Black wards knitting together, thick and stubborn, the kind designed to keep things in, not out. The storm outside rattles the windows, rain streaking down ancient glass etched with family runes Sirius never fully scraped away.

“Absolutely not,” Sirius says, already moving, boots thudding across the hall. His accent sharpens when he’s angry, pure London bite, old-money vowels flattened by years of rebellion. He clicks his rings together once, twice. A tell.

Lyra sits on the rug by the sofa, completely unconcerned, lining up toy broomsticks by size. She looks up at you first. Then at him.

“We’re locked,” she says calmly, like she’s announcing the weather.

Sirius exhales through his teeth. “Yeah, sweetheart. I noticed.”

You and Sirius haven’t shared a room in over a decade. The last time involved raised voices, wand sparks, and an audience that definitely shouldn’t have been cheering. Hogwarts taught you exactly how much you disliked each other, and neither of you ever revised that opinion.

Until now.

“Tell me this isn’t your fault,” you say, arms folded.

He laughs, too loud, too quick. “Love, if this were my fault, the house would be on fire and we’d be drunk.”

He mutters something under his breath in French as he tests the door, then switches to clipped Latin when the wards bite back. Old magic. Stubborn magic. The kind tied to blood and inheritance. His jaw tightens.

Lyra scoots closer to his leg without looking scared. He automatically shifts, placing himself between her and the door. You clock it. He pretends you didn’t.

“It’s temporary,” he says, finally turning to you. His eyes flick over you like he’s bracing for impact. “Storm-triggered containment. Wards won’t lift until the pressure drops.”

“And how long is that?”

He shrugs. Defensive. Honest. “A day. Maybe two.”

Silence stretches dangerous, loaded. The kind he hates.

Lyra breaks it by holding up a broom. “You’re both loud when you’re mad.”

Sirius snorts despite himself. “You get that from me.”

She gives him a look identical to his own and then looks back at you, curious but unreadable.

You’re locked in Sirius Black’s house. With the man you hated at seventeen. With the child he would burn the world down for.

And none of you are leaving anytime soon.

Sirius drags a hand through his hair, already pacing. “Right. Ground rules.”

You arch a brow. “You hate rules.”

“I hate other people’s,” he corrects. His voice drops, serious now. “Mine keep her safe.”

He looks at you, not challenging. Assessing.

“Don’t disappear,” he says. “Don’t lie. And don’t scare her.”

Lyra smiles faintly, like she already knows something neither of you do.

Outside, thunder rolls.

Inside, the story starts.