One of the guards bent down to graze the blue liquid with his finger. The moment he touched it he cried out and jumped back, flapping his hand to shake the stuff off. If the jar was freezing, I could only imagine how cold the blue stuff was.

“What a waste,” Caul said. “I would have liked to combine that with a few other choice souls.”

“Aswindan,” Bentham recited. “Root word swind. Meaning shrink. Be glad you didn’t take that one, brother.”

Caul frowned. “No. No, I’m certain I was right.”

“You’re not,” said Miss Peregrine.

His gaze darted between them, paranoid, as if he were weighing the possibility they might somehow be in league against him. Then he seemed to let it go. “This is just the first room,” he said. “The better souls are deeper in, I’m sure.”

“I agree,” said Bentham. “The farther we go, the older the souls will be, and the older the soul, the more powerful.”

“Then we shall plumb the very heart of this mountain,” said Caul, “and eat it.”

* * *

We were prodded through one of the black doors, pistols at our ribs. The next room was much like the first, with coves combing its walls and doors leading into the dark. There were no windows, though, and just a single blade of afternoon sun slicing down the dusty floor. We were leaving daylight behind us.

Caul ordered Emma to make a flame. He ordered me to inventory the contents of the walls. I duly reported three jars, but my word wasn’t enough; he made me tap each one with my fingernail to prove it was there, and pass my hand through dozens of empty coves to prove they were vacant.

Next he made me read them. Heolstor. Unge-sewen. Meagan-wundor. The words were meaningless to me, unsatisfactory to him. “The souls of piddling slaves,” he complained to Bentham. “If we’re to be kings, we need the souls of kings.”

“Onward, then,” said Bentham.

We plunged into a baffling and seemingly endless maze of caverns, daylight a memory, the floor sloping ever downward. The air grew colder. Passageways branched off into the dark like veins. Caul seemed to navigate by some sixth sense, confidently bounding left or right. He was insane, manifestly insane, and I was sure he was getting us so lost that even if we managed to escape him, we could expect to spend eternity trapped in these caves.

I tried to imagine the battles that had been waged over these souls—ancient, titanic peculiars clashing among the spires and valleys of Abaton—but it was too mind-boggling. All I could think of was how terrifying it would be to be trapped down here without a light.

The farther we went, the more jars were in the walls, as if plunderers had long ago raided the outermost rooms but something had stopped them from getting too far—a healthy sense of self-preservation, maybe. Caul barked at me for updates, but he’d stopped demanding proof of which coves were occupied and which were vacant, and only occasionally made me read a jar’s label aloud. He was hunting bigger game and seemed to have decided there was little worth bothering with in this part of the library.

We went on in silence. The rooms grew larger and grander, in their crude way, the ceilings rising and walls widening. The jars were everywhere now: filling every cove, stacked in totemic pillars in the corners, wedged into cracks and crevices, the cold that seeped from them refrigerating the air. Shivering, I pulled my arms close to my body, my breath pluming before me, the watched feeling that had haunted me earlier creeping back. This library, so-called, was a vast underworld, a catacomb and hiding place for the second soul of every peculiar who had ever lived, prior to the last millennium—hundreds of thousands of them. That great accretion of souls had begun to exert a strange pressure on me, compressing the air spaces in my head and lungs as if I were sinking gradually into deep water.

I wasn’t the only one feeling out of sorts. Even the guards were skittish, startling at small noises and checking constantly over their shoulders.

“Did you hear that?” mine said.

“The voices?” said the other one.

“No, more like water, rushing water …”

While they talked I stole a quick glance at Miss Peregrine. Was she frightened? No—she seemed to be biding her time, waiting and watching. I took some comfort in that, and in the fact that she could have taken bird form and escaped her captors long ago, but hadn’t. So long as Emma and I were prisoners, she would be. Maybe that was more than just her protective instinct at work. Maybe she had a plan.

The air grew colder still, a thin sweat on my neck turning steadily to ice water. We trudged through a chamber so littered with jars I had to hopscotch around them to keep from kicking them over—though everyone else’s feet passed right through them. I felt suffocated by the dead. It was standing-room only here, the platform of a rush hour train station, Times Square on New Year’s Eve, all the revelers slack-faced and staring, unhappy to see us. (I could feel this, if not quite see it.) Finally, even Bentham lost his nerve.

“Brother, wait,” he said, breathless, holding Caul back. “Don’t you suppose we’ve gone far enough?”

Caul turned slowly to look at him, his face split evenly by shadow and fire-glow. “No, I do not,” he said.

“But I’m sure the souls here are sufficiently—”

“We haven’t found it yet.” His voice sharp, brittle.

“Found what, sir?” my guard ventured.

“I’ll know it when I see it!” Caul snapped.