Their room was on the second floor.
Grimmauld Place had clearly been grand once, in the way old money was grand — heavy furniture, dark wood, ornate plasterwork beginning to separate from the ceiling. Harry and the others had been cleaning for a month, and it showed in some rooms, but the bones of the house were stubborn.
Harry and Ron took the same room as Kevin. The girls took the one next door. Between the bedrooms, a small sitting room looked out over the back of the house, and it was there the group gathered to catch up on the month they'd spent apart.
Ron and the twins compared notes on the Apparition tests they'd nearly attempted. Harry talked through what the Order had been doing — reconnaissance, mostly, watching Death Eater movements without getting close enough to provoke anything. Sirius had spent most of the summer at Hogwarts with Dumbledore and only recently returned to Grimmauld Place.
Kevin listened with half his attention. The other half was on a low cabinet in the corner of the sitting room, where a pile of objects had been stacked during the cleaning — the discarded junk of generations of Blacks, gathered together and left for someone to decide what to do with.
The vibe coming off that pile was wrong.
"Kevin's already got into alchemy this summer," Harry was telling Ron, nodding toward the energy storage crystal that Kevin had put on the table. "Made that in about two weeks."
"Can I—?" Ron reached for it.
"Carefully," Kevin said, not looking up.
He crossed to the cabinet.
"Careful with the music box," Harry called after him. "It's got some kind of charm on it — makes you want to fall asleep."
Kevin moved the music box aside without touching its clasp and kept looking.
There.
A heavy locket. Silver edging. The surface a dull brownish-silver, slightly tarnished. The chain coiled beneath it like something sleeping.
He knew it immediately. Not from any spell or diagnostic — just the feeling of it. The same quality the diary had carried. The same sense of something compressed into a container it had never been meant for, pressing outward.
He picked it up.
He tried the clasp. It didn't give. He tried with more pressure — forty points of Constitution behind his grip, which was considerably more force than a human being had any natural right to — and the locket didn't move.
Kevin's expression went very still.
A fake would have opened. A normal cursed object might resist, but not like this.
His mind ran the timeline. In the film, Dumbledore and Harry nearly die retrieving the locket from a sea cave, only to discover they've recovered a worthless copy. While the real one had been sitting in the house that served as their headquarters. Recovered during cleaning. Tossed in a junk pile.
How long had it been here? Since Regulus Black. Which meant for sixteen years, Voldemort's fifth Horcrux had been gathering dust in the Order of the Phoenix's future safe house.
"Kevin." Harry was watching him from across the room. "That locket's probably cursed. Nobody's managed to open it."
"Made me feel off when I first found it," he added. "I couldn't explain it. Just — wrong."
"Puts me in mind of Voldemort's diary," Kevin said.
The room went quiet.
He didn't look up from the locket. He just waited, letting the comparison settle.
Harry's expression shifted. "Kevin, what are you—"
Kevin was already pulling the crowbar from his bag.
Three quick charms ran down the steel — reinforcing the hardness and density of the metal until it was something other than ordinary iron. He pressed a fourth into the table, locking it to the floor so it wouldn't simply drive through the old wood and into the room below.
Harry and the others caught on fast and stepped back without being told. Even Ron moved.
Kevin set his grip, raised the crowbar, and swung.
The impact shook the room like a thunderclap. The floor vibrated underfoot. Plaster dust sifted from the ceiling. The table, despite the reinforcement, drove itself flush with the floorboards — the legs didn't break, they just compressed, hammered down like posts into soft earth.
Smoke and disturbed dust hazed the air.
"Kevin!" Hermione had lunged forward; Harry caught her arm on instinct.
"I'm fine." Kevin waved the smoke away.
He reached into the debris. The locket sat there, completely unmarked. Not a scratch. Not even tarnish displaced.
Feet pounded on the stairs. Sirius burst through the door with his wand up, Lupin and Moody behind him. Mrs. Weasley appeared at the back, hand to her mouth.
They scanned the room. The collapsed table. The ceiling crack that hadn't been there before. Kevin standing in the middle of it all, holding a locket.
"What in the—" Sirius started.
"I need Dumbledore," Kevin said. He held up the locket. "This is connected to Voldemort. Significantly."