"Don't," Alistair said before anyone else could move.
His voice was pitched low and level, in a way Ethan hadn't heard from him yet not performance, not dry wit, just a man doing very careful math about the room he was standing in.
"Whatever you're about to do, Rennick, understand that we are four against your one, and that math does not improve for you by talking longer."
"Four against one," Rennick agreed pleasantly, "assuming I'm the only variable in this room."
He reached into his coat slow and deliberate, with no threat in the movement at all and drew out a single vial, identical to the ones on the table.
Except this one wasn't stoppered.
It wasn't residue.
The green-gold light inside it moved the way Ethan's own coal moved when it was agitated.
Awake.
Aware.
"You're not harvesting them for study," Idris said slowly.
Understanding arrived on his face like a physical weight.
"You're collecting them."
"Every door needs a key," Rennick said, and his smile didn't waver even slightly.
"Karrathess doesn't open for nothing, gentlemen. It opens for a price, paid in exactly the currency I've spent three months very patiently gathering."
He nodded, almost courteously, toward Ethan.
"Though I'll admit, you're the interesting complication. The boy who ate his key instead of dying with it."
His smile widened.
"I'd love to know how you managed that, purely from professional curiosity."
The coal in Ethan's chest went very still.
Not the stillness of fear this time.
Something colder.
Recognition again, but wrong-shaped.
Not kin.
Enemy, it said.
The clearest single word it had ever given him.
That one. Enemy of the door. Enemy of us both.
Ethan filed the reaction away even as it landed.
His own Cthu had never once agreed with him about anything before tonight, and the fact that it hated Rennick more than it hated him was, in its own strange way, useful information.
Whatever Rennick was building toward, it wasn't a version of Karrathess that either side of that door actually wanted opened.
"You're trying to open it," Ethan said aloud, working it through even as he spoke.
"Not close it."
His eyes remained on Rennick.
"You want whatever's on the other side of Karrathess to get through."
"Close it?"
For the first time, something like genuine amusement cracked Rennick's composure.
"Boy, nobody in this city has been trying to close anything."
His smile returned.
"Your Vigil puts out fires."
He lifted the vial slightly.
"I'm trying to see what's underneath one."
The green-gold light inside the glass pulsed.
"And I am forgive the immodesty very nearly there."
He raised the open vial, and the green-gold light inside surged toward the ceiling like a flame catching a draft.
"So," Rennick said, still smiling, still unhurried, "shall we discuss this like reasonable people?"
His gaze moved across the room.
"Or would you prefer I finish what your little friend upstairs so rudely interrupted last night?"
Every ward in the house began, all at once, to burn.