He didn’t see me.

I waited for his footsteps to recede and then squeezed into the hall. Emma followed, pulling the door shut behind us.

Left or right? The floor ran uphill to the left, downhill to the right. According to Bentham we were in Caul’s tower, but his prisoners were not. We needed to get out. Down, then. Down and right.

We turned right, hugging the inner wall as the hallway spiraled downward. The rubber soles of my shoes squeaked. I hadn’t noticed the noise until now, and in the amplified quiet of the hard-walled hallway, each step was cringe-inducing.

We went on for a short while, and then Emma tensed and threw her arm across my chest to stop me.

We listened. With our footsteps silenced, we could hear others. They were ahead of us, and close. We rushed to the closest door. It slid open easily. We dove inside, closed it, threw our backs against it.

The room we’d entered was round, walls and ceiling both. We were inside a huge drainage pipe, thirty feet wide and still under construction—and we weren’t alone. Where the pipe ended and broke into rainy daylight, a dozen men sat on a pipe-shaped scaffold, staring at us, dumbfounded. We’d interrupted them during their lunch break.

“Hey! How’d you get in there?” one shouted.

“They’re kids,” said another. “Hey, this ain’t a playground!”

They were American, and they didn’t seem to know what to make of us. We didn’t dare respond for fear that the wights in the hall might hear us, and I worried that the workers’ shouting would attract their attention, too.

“Have you got that finger?” I whispered to Emma. “Now seems like a good time to test it out.”

So we gave them the finger. By which I mean we put on the dust masks (wet from the stream but still serviceable), Emma crushed a tiny bit of Mother Dust’s pinky, and we walked down the pipe toward the men and attempted to launch the powder at them. First Emma tried blowing it out of her cupped hand, but it just swirled into a cloud around our heads, which made my face tingle and go a bit numb. Next I tried throwing it, which didn’t work at all. The dust, it seemed, wasn’t much good as an offensive weapon. By now the pipe builders were growing impatient, and one had jumped down from the scaffold to remove us by force. Emma tucked the finger away and made a flame with her hand—there was a poof! as Emma’s flame ignited the dust hanging in the air, turning it instantly to smoke.

“Woah!” the man said. He began coughing and soon slumped to the floor, fast asleep. When a few of his friends ran to help him, they too fell victim to the cloud of anesthetizing smoke and fell to the ground beside him.

Now the remaining workmen were afraid, angry, and shouting at us. We ran back to the door before the situation could devolve further. I checked that the coast was clear and we slipped into the hall.

When I closed the door behind us, the sound of the men’s voices was muted completely, as if it hadn’t just shut them inside but had somehow turned them off.

We ran a short way, then stopped and listened for footsteps, then ran, then stopped and listened, spiraling down the tower in stuttering bursts of action and silence. Twice more we heard people coming and ran to hide behind doors. Inside one was a steaming jungle echoing with the screams of monkeys, and another opened into an adobe room, beyond which lay hard-packed ground and looming mountains.

The floor leveled and the hallway straightened. Around the last bend was a pair of double doors with daylight gleaming beneath them.

“Shouldn’t there be more guards around?” I said nervously.

Emma shrugged and nodded toward the doors, which appeared to be the only way out of the tower. I was about to push them open when I heard voices on the other side. A man telling a joke. I could hear only the burble of his voice, not the words, but it was definitely a joke, because when he finished there was an eruption of laughter.

“Your guards,” Emma said, like a waiter presenting a fancy meal.

We could either wait and hope they went away, or open the door and deal with them. The latter option was braver and faster, so I summoned New Jacob and told him we were going to throw open the door and fight, and to please not discuss the matter with Old Jacob, who inevitably would whine and resist. But by the time I’d gotten it all settled, Emma was already doing it.

Silently and quickly, she pulled open one of the swinging doors. Arrayed before us were the backs of five wights in mismatched uniforms, all wearing modern police-issue-type pistols at their waists. They were standing casually, facing away from us. None had seen the door open. Beyond them was a courtyard surrounded by low barracks-like buildings, and rising in the farther distance was the fortress wall. I jabbed my finger toward the finger hidden in Emma’s pocket—sleep, I mouthed, by which I meant that rendering these wights unconscious and then dragging them inside the tower seemed the most expedient course of action. She understood, pulled the door halfway closed, and began to dig out the finger. I reached for the dust masks, which were stuffed into my waistband.

And then a flaming mass of something flew over the fortress wall in the distance, sailed toward us through the air in a graceful arc, and fell splat in the middle of the courtyard, spraying dribbly blobs of fire everywhere and sending the guards into a state of excitement. Two ventured to see what had landed, and as they bent over to examine the flaming muck, another hunk came sailing over the wall and hit one of them. He was sent sprawling, his body aflame. (From the smell of it, which was pungent and traveled fast, it was a mixture of gasoline and excrement.)