“We won’t,” I said, and walked through the doorway.

We followed Bentham’s assistant into the room, past the usual furnishings, through the missing fourth wall, and out into a thick grove of evergreens. It was midday, late fall or early spring, the air chill and tinged with wood smoke. Our feet crunched along a well-worn path, the only other sounds a songbird’s whistle and the low but rising roar of falling water. Bentham’s assistant said little and that was fine by us; Emma and I were filled with a high, buzzing tension and had no interest in idle conversation.

We passed through the trees and out onto a track that curved around a mountainside. A desaturated landscape of gray rocks and patches of snow. Distant pines like rows of bristling brushes. We jogged at a moderate pace, careful not to exhaust ourselves too soon. After a few minutes we rounded a bend and found ourselves standing before a thundering waterfall.

Here was one of the signs Bentham had promised. THIS WAY, it read, plain as day.

“Where are we?” Emma asked.

“Argentina,” the assistant replied.

Obeying the sign, we followed a path that became gradually overgrown with trees and thickets. We pushed aside the brambles and trudged on, the waterfall quieting behind us. The path ended at a small stream. We followed the stream a few hundred yards until it, too, ended, the water flowing into a low opening in a hillside, the entrance to which was hidden by ferns and moss. The assistant knelt on the stream bank and pulled back a curtain of weeds—then froze.

“What is it?” I whispered.

He pulled a pistol from his belt and fired three shots into the opening. A chilling cry came back, and then a creature rolled out into the stream, dead.

“What is it?” I asked again, staring at the creature. It was all fur and claws.

“Dunno,” said the assistant. “But it was waiting for you.”

It was nothing I could identify—it had a lumpy body, fanged teeth, and giant bulbous eyes, and even they seemed to be covered with fur. I wondered if Caul put it there—if maybe he’d anticipated his brother’s plan and booby-trapped all the shortcuts into his Panloopticon.

The stream carried the body away.

“Bentham said he didn’t have any guns,” Emma said.

“He doesn’t,” the assistant said. “This one’s mine.”

Emma looked at him expectantly. “Well, could we borrow it?”

“No.” He put it away. Pointed to the cave. “Go through there. Retrace your steps backward to the place we came from. Then you’ll be with the wights.”

“Where will you be?”

He sat down in the snow. “Here.”

I looked at Emma and she looked back, both of us trying to hide how vulnerable we felt. Trying to grow a sheath of steel around our hearts. For what we might see. Might do. Might be done to us.

I descended into the stream and helped Emma in. The water was numbingly cold. Bending to peer into the cave, I saw daylight glinting dimly at the other end. Another changeover, darkness into light, pseudo-birth.

There appeared to be no more toothy creatures waiting inside, so I lowered myself into the water. The stream rushed up over my legs and waist in a freezing swirl that took away my breath. I heard Emma gasp behind me as she did the same, and then I grabbed the lip of the cave and slid inside.

Being immersed in cold, rushing water hurts like being stabbed with needles all over your body. All pain is motivating, and this type especially so; I scrabbled and pushed myself through the stone tunnel with a quickness, over slick sharp rocks and low under-hangs, half choking as water flowed over my face. Then I was out, and turned to help Emma.

We jumped out of the freezing stream and looked around. The place was identical to the other side of the cave except there was no assistant, no bullet casings in the snow, no footprints. As if we’d stepped through a mirror and into the world it reflected, minus a few details.

“You’re blue,” Emma said, and she pulled me up onto the bank and held me. Her warmth coursed through me, bringing feeling back to numbed limbs.

We walked, retracing every step of the route we’d taken. We found our way back through the brambles, up the hill, past the waterfall—all the scenery just the same except for the THIS WAY sign Bentham had set out for us. It was not here. This loop did not belong to him.

We arrived again at the small forest. Darted from tree to tree, using each one as cover until we reached the place where the path ended and became a floor and then a room, framed and hidden by a pair of crossed firs. But this room was different from Bentham’s. It was spartan—no furnishings, no poppy-laced wallpaper—and the floor and walls were smooth concrete. We stepped inside and searched the darkness for a door, running our hands along the walls until I happened to hook a small recessed handle.

We pressed our ears to the door, listening for voices or footsteps. I heard only vague echoes.

Slowly, carefully, I slid the door open a crack. Inched my head through the gap to peek out. Here was a wide curving hall of stone, hospital clean and blindingly bright, its smooth walls toothed with tall, black, tomblike doors, dozens of them curving away sharply.

This was it: the wights’ tower. We had made it inside the lion’s den.

* * *

I heard footsteps approaching. Pulled my head back inside the door. There was no time to close it.

Through the crack I glimpsed a flash of white as a man walked by. He was moving quickly, dressed in a lab coat, head down to read a paper in his hand.