The mountain did not announce itself the way mountains were supposed to announce themselves.
KaSandra had walked out of the darkness-between-places with Thomas held against her chest and expected — the way a body expects cold after cold, having walked this exact path more times than she had ever told the house — the specific shock of thin air and worse footing that always came first. Instead there was only stillness, a white and endless quiet that had no wind in it at all, snow that did not fall so much as simply exist, suspended in the air the way a held breath is suspended, waiting for something to release it.
She knew the way. She had always known the way, since before she understood what the way led to, and her feet found the path up through the white without her needing to look for it, an old habit of the body that had outlasted every other habit she'd built since. Thomas was very still against her. Too still. She had been telling herself, since the darkness swallowed them both in the kitchen, that his stillness was the sleep she had put him in and nothing more, and she kept telling herself that now, because the alternative was a thought she did not have room to hold while she was walking.
The gate came into view the way it always came into view — not built, exactly, more grown, an arch of pale stone that seemed to have simply occurred where the mountain decided an arch should be, vines with small white flowers wound through it despite an altitude that should have killed anything green a thousand feet below. Two women stood at either side of it, in the plain unadorned robes the coven wore, and KaSandra recognized both of them, though it had been years, and years here meant something different than years meant in the house below.
"KaSandra Lucas," one of them said. Her name was Wren, or had been the last time KaSandra stood at this gate. Her expression did not change at the sight of what KaSandra was carrying. Very little at this gate ever changed its expression at anything. "You've been away a long time."
"I know how long I've been away," KaSandra said. "I need to see the healers. Now. Not after the customary greeting, not after whatever accounting you keep of who has and hasn't visited recently. Now."
Wren's eyes moved to Thomas.
"What happened to him."
"A poison built to survive being found. It's already three hours into a body that wasn't built to survive it for three hours, let alone however much longer it's going to take you to decide whether I've earned the right to ask for help." KaSandra heard her own voice rising and did not try to stop it, which was its own kind of tell, because KaSandra's voice did not rise, had not risen in longer than most of the house had known her. "Please."
The word cost her something to say. Wren heard the cost in it, KaSandra could see her hearing it, and something in the healer's plain composed face shifted for the first time.
"Come," Wren said, and the gate opened the way it always opened, without visible mechanism, simply present and then simply passable.
The healing hall was carved into the mountain itself, warm in a way the outside world was not, lit by something that was not quite fire and not quite light, the specific gold-white glow the coven produced without ever explaining how. KaSandra laid Thomas on the stone table at its center — worn smooth by a use older than the house, older than the chosen ones, older, KaSandra suspected, than the demon queen herself — and stepped back only far enough to let the healers work, refusing, when Wren gestured toward the door, to leave the room at all.
"I'm not going anywhere," KaSandra said.
"You never do," Wren said, without heat, and set to work.
There were three of them now, gathered around the table, hands moving over Thomas in patterns that meant nothing to KaSandra's eye and everything, she trusted, to theirs. She watched the gold-white light gather at their fingertips and sink into Thomas's skin, watched his chest rise and fall in the artificial evenness of the sleep she'd put him in, watched for some sign — any sign — that the poison was retreating instead of simply waiting them out the way it had been built to wait everything out.
"It's resisting," one of the healers said, after a long silence. Her name KaSandra did not know — younger than Wren, unfamiliar, someone who must have joined the coven in the years KaSandra had stayed away. "Whatever made this understood exactly what we'd try first. It's built around our methods specifically. Not generally. Specifically."
"That's not possible," Wren said. "No one outside the coven knows our methods well enough to build around them."
"Someone does," the healer said. "Or someone who trained under someone who does."
KaSandra felt something cold move through her that had nothing to do with the mountain air.
"How specifically," she said.
The young healer looked up at her, and something in her face — not unkind, but careful, the careful of someone about to say a thing that would cost the person hearing it a great deal — made KaSandra's chest tighten before a single word had been spoken.
"The compound has a signature," the healer said. "A structure. I've seen it before, though only once, a very long time ago, in a text most of the coven has stopped teaching because the person who wrote it stopped being someone we spoke of." She looked at Wren, as if for permission, and Wren, after a long moment, gave the smallest possible nod. "It bears the fingerprints of your sister's early work."
The hall went very quiet.
"Patricia is dead," KaSandra said. Flat. Final. The way she said things she had built her entire life around not questioning.
"I didn't say she made it," the healer said, gently. "I said it bears her fingerprints. There's a difference, and I think — forgive me, I don't know you well enough to know how much this will cost you to hear — I think you already understand the difference better than I do."
KaSandra looked down at Thomas, at the gold-white light sinking uselessly into skin that would not release what had been put into it, at the specific stubborn architecture of a poison built by someone who had understood exactly which door the coven's healing would try first because they had once stood inside these walls and learned every door there was.
"Keep working," she said, and her voice had gone somewhere very far away from her, somewhere cold and quiet and entirely unlike the voice that had begged at the gate an hour before. "I'll deal with the rest of it after he's safe."
"KaSandra—"
"After," she said, and Wren, wisely, did not push further.
The healers bent back to their work, the gold-white light gathering and sinking and gathering again, patient the way the mountain was patient, and KaSandra stood over the man she had said yes to in a garden that felt, now, like it belonged to a different lifetime entirely, and made herself a promise in the cold quiet part of her mind that had learned, a long time ago, how to make promises it fully intended to keep no matter what they eventually cost.
Whoever had built this poison out of pieces of her dead sister's oldest secrets was going to answer for it.
She simply had not yet decided what the answering would look like.