Grimmauld Place looked the same. Sirius half expected it to change now that Regulus is here, but it still had that dark quality that he hated.
Regulus had already made himself at home in the library.
Of course he had.
"I still cannot believe you told them about the Horcrux," Regulus said, without looking up from the shelf he was examining. His voice had the flat quality he used when he was more concerned than he wanted to appear. "That is not information to be shared lightly, Sirius."
"I'm aware of that," Sirius said. "I also watched you nearly die at the bottom of a lake because you tried to handle one alone. I'm not making that mistake twice." He crossed his arms. "You can't do this research by yourself. You need resources, you need protection, and you need people who understand what's at stake. Isaac and the Custodians are the most qualified people I know, and I trust them with my life. I've trusted them with my children. This is not different."
Regulus was quiet for a moment. "It's different," he said. "But I take your point."
He turned from the shelf and looked at Isaac, who was standing in the center of the library with his hands in his coat pockets and the expression of a man who had already assessed the room and found it satisfactory.
"The ICW will provide whatever resources we can," Isaac said. "Research access, specialist consultation, containment equipment. We have people who have spent careers studying Dark artefacts — none of them have encountered anything precisely like this, but the knowledge base is there, and they are discrete and won't ask questions." He paused. "We are very motivated to help. The last thing anyone wants is another dark lord deciding Europe is an appropriate venue for his ambitions."
"How did the Ministry take the cave report?" Sirius asked.
"Not well," Wyatt said from the doorway, where he had positioned himself with his shoulder against the frame and his hat at its customary angle. "They weren't thrilled about a group of ICW agents operating on British soil without notification. Told them we were in the area on vacation and stumbled across it." He paused. "Don't think they believed us. But they were considerably more concerned about six hundred Inferi sitting in a cave on their coastline than about our paperwork, so we got away with it."
"They've mobilized to seal it," Beatriz added. She was leaning against one of the bookcases with her arms crossed, her eyes moving along the shelves with the professional attention of someone cataloguing potential resources. "I heard someone in the Auror office is considering using it as a training ground."
"That sounds like Moody," Sirius said.
"It does," Isaac agreed, with the expression of a man who has met Alastor Moody and found him both impressive and exhausting in equal measure.
Sirius looked at Wyatt. "I thought you were returning to North America."
"Change of plans," Wyatt said, with the slow smile that meant the change of plans had a specific reason he was not going to volunteer but would confirm if asked. "Taking a post here in Europe for a while. Thought I'd see more of the continent."
"He means he's staying for the French healer," Beatriz said flatly.
"I mean I'm staying for the considerable professional opportunities available in—"
"Wyatt," Sirius said.
"Fine. Both." Wyatt's smile didn't waver. "A man can have more than one reason."
"That boy is Esme's mentee," Sirius said. "You hurt him and she will come after you personally. I want to be clear that I will not intervene."
"I appreciate the warning," Wyatt said, with the tone of a man who does not find warnings particularly discouraging.
"Ugh," Beatriz said.
Isaac produced the box.
It was black and heavy, lead-lined, the kind of container that didn't need to announce its enchantments because they were evident in the way the air around it felt. He set it on the library table with the careful deliberateness of someone who has been trained to handle objects like this and has not forgotten why the training exists.
"For the locket," he said. "Until you find a method of destruction. We don't know whether the containment will hold indefinitely but it will prevent accidental contact and limit the influence." He looked at Regulus steadily. "We've seen what prolonged exposure to objects like this does to people. Don't handle it without protection. Don't keep it near where you sleep."
Regulus looked at the box for a moment. Something crossed his face that was not quite recognition and not quite dread but was related to both.
"Understood," he said.
"Keep us informed," Isaac said, looking between the two brothers. "Whatever you find, whatever you need — you contact me directly. This doesn't go through official channels until we decide together that it should." He paused. "And Regulus — what you're attempting has never been done. That means we have no framework for how long it takes or what it costs. Don't let the urgency of it make you careless."
Regulus looked at him with the expression of a man receiving advice he has already given himself and is choosing to receive graciously anyway. "I won't."
The Custodians took their leave in the way they did everything. Efficient and without ceremony.
Then it was just the two of them. Sirius and Regulus and the library and the box on the table between them.
Sirius looked at his brother. At the library shelves already half-examined, at the methodical quality of a man who had woken from five years of suspension and gone immediately back to work, who had a task and intended to see it finished and was not interested in being told it was impossible.
"You'll send word if you need anything," Sirius said. It wasn't a question.
"I'll send word," Regulus confirmed.
"And you'll eat. Kreacher will make sure of it but I'm saying it anyway."
"I'll eat, Sirius."
"And you won't—"
"Sirius." Regulus looked at him with the patient expression of a younger brother who has been managed by an older one for long enough to recognize the pattern. "Go home. Go to your wife and your four children." The almost-smile appeared, thin and real. "I have work to do."
Sirius looked at him for a moment longer than necessary. Then he nodded once.
Regulus nodded back.
Sirius apparated home. He stood in the entrance hall of Blacktide for a moment, listening to the sounds of the castle. Alphard's voice from somewhere above, decisive and carrying, and underneath it the lower murmur of Esme talking to someone, and what might have been Corvus laughing.
He thought about Uncle Marius. About the visit that needed to happen. Those two still didn't know that he and Esme officially got married and had fully adopted the boys.
Soon, he thought. He would go soon.
But tonight — tonight he was home.