“Spreading it between multiple casters may have diluted the feedback.”

“That is not remotely how it works,” said Ianthe.

“Oh, God, here comes the expert,” Naberius said.

“Babs,” said Ianthe’s sister hurriedly, “you’re getting hangry. Let’s go find some food.”

Gideon watched her necromancer’s gaze fix on Ianthe Tridentarius. Ianthe did not notice, or affected not to notice; her eyes were as pale and purple and calm as they ever were, but Harrowhark was quivering like a maggot next to a dead duck. As the Third traipsed out—as noisy as if they were leaving a play, not a sickroom—Harrow’s eyes went with them. Gideon said aloud, “Hey. Palamedes. Do you need someone to stay with her?”

“I will,” said Teacher, before Palamedes could respond. “I will move my bed here. I will not leave her alone again. Whenever I must leave my post one of the other priests will take my place. I can do that much, at least … I am not afraid, nor do I have better things to do with my time. Whereas—I am very much afraid—you do.”

Gideon allowed herself a lingering look at Dulcinea, who made for a more beguiling corpse than her stolid dead cavalier ever did: lying on the bed looking nearly transparent with streaks of drying, bloodied mucus on her chin. She wanted to help, but out of the corner of her eye she saw Harrow moving out of the doorway and into the corridor—staring after the disappearing Third—and she steeled herself to say, “Then we’re out. Can you—let us know if anything changes?”

“Someone will come for you,” said Teacher gently.

“Cool. Palamedes—”

He met her eye. He had taken off his glasses and was cleaning them with one of his innumerable handkerchiefs.

“Ninth,” he said, “if she were capable of anything, in order to become a Lyctor—don’t you think she’d be one already? If she really wanted to watch the world burn—wouldn’t we all be alight?”

“Stop flattering her. But—thanks,” said Gideon, and she darted off into the corridor after Harrow.

31

IN THE CORRIDOR, HER necromancer was staring distantly down the passageway at the disappearing hems of the Third: her brow had furrowed a wrinkle into her paint. Gideon had intended to—she had intended to do a lot of things; but Harrow left her no opening for the actions she’d planned and offered none of the answers she’d wanted. She simply turned in a swish of black cloth and said, “Follow me.”

Gideon had prepared beforehand a fuck-you salvo so long and so loud that Harrow would have to be taken away to be killed; but then Harrow added, “Please.”

This please convinced Gideon to follow her in silence. She had more or less expected Harrow to lead with “What were you doing in my closet,” at which point Gideon might well have shaken her until the teeth in her head and the teeth in her pockets all rattled. Harrowhark swept down the stairs two at a time, the treads creaking in panic, as they went down the grand flight that led them to the atrium: from there, down one corridor, down another, one left, and then down the steps to the training rooms. Harrow ignored the tapestry that would have taken them to the hidden corridor and the ransacked Lyctor laboratory where Jeannemary had died, and instead pushed open the big dark doors to the pool.

Once there, she tossed down two grubby knuckles from her pockets. A substantial skeleton sprang from each, unfurling. They stood before the door, linked elbows, and held it shut. She scattered another handful of chips like pale grain; skeletons rose, forming and expanding the bone as though bubbling up from it. They made themselves a perimeter around the whole room, pressing the knobbles of their spines against the old ceramic tile and standing to attention. Shoulder to shoulder they stood, as though bodyguards, or hideous chaperones.

Harrow turned to face Gideon, and her eyes were as black and inexorable as a gravity collapse.

“The time has come—”

She took a deep breath; and then she undid the catches to her robes, and they fell away from her thin shoulders to puddle around her ankles on the floor.

“—to tell you everything,” she said.

“Oh, thank God for that,” said Gideon hysterically, profoundly embarrassed at how her heart rate had spiked.

“Shut up and get in the pool.”

This was so unanticipated that she didn’t bother to question, or to complain, or even to hesitate. Gideon unhooked her robe and hood and pulled off her shoes, unstrapped her rapier and the belt that held her gauntlet. Harrow seemed ready to enter the greenly lapping waves wearing her trousers and shirt, so Gideon figured Oh well, what the hell and made the plunge almost fully clothed. She jumped in recklessly: tidal waves exploded outward at her passing, peppering the stone sides of the pool with droplets, gushing and foaming. The seamy, distasteful feeling of water seeping through her underwear hit her all at once. Gideon spluttered, and ducked her head beneath, and spat out a mouthful of liquid that was warm as blood.

After a moment’s consideration, Harrow stepped in too—walking off the side carelessly, slipping beneath the water like a clean black knife. She disappeared beneath the surface, then emerged, gasping, spluttering in a way that ruined everything about the portentous entrance. She faced Gideon and trod water, flapping her arms a little before she managed to get her toes touching the bottom.

“Are we in here for a reason?”

Their voices echoed.

“The Ninth House has a secret, Nav,” said Harrow. She sounded calm and measured and frank in a way she’d never been before. “Only my family knows of it. And even we could never discuss it, unless—this was my mother’s rule—we were immersed in salt water. We kept a ceremonial pool for the purpose, hidden from the rest of the House. It was cold and deep and I hated every moment I was in it. But my mother is dead, and I find now that—if I really am to betray my family’s most sacred trust—I am obliged at the least to keep, intact, her rule.”

Gideon blinked.

“Oh shit,” she said. “You really meant it. This is it. This is go time.”

“This is go time,” agreed Harrowhark.

Gideon swept both of her hands through her hair, trickles going down the back of her neck and into her sodden collar. Eventually, all she said was, “Why?”

“The reasons are multitudinous,” said her necromancer. Her paint was wearing off in the water; she looked like a grey picture of a melting skeleton. “I had—intended to let you know some of it, before. An expurgated version. And then you looked in my closet … If I had told you my suspicions about Septimus’s meat-puppet on the first day, none of this would have happened.”

“The first day?”

“Griddle,” said Harrow, “I have not puppeted my own parents around for five years and learned nothing.”

Anger did seep into Gideon then, along with a couple more litres of salt water. “Why the hell didn’t you tell me when you killed him?”

“I didn’t kill him,” said Harrowhark sharply. “Someone else did—blade through the heart, from what I saw, though I only got a few minutes to look before I had to run. I only had to push the theorem the most basic bit before he came apart. I took the head and left when I thought I heard someone coming. This was the night after we completed the entropy field challenge.”