As the dust settled, we could see the trunk leaning over the wall, a decent, if wobbly, bridge for climbing up to the top of the twelve feet of brick. We’d knock down another tree next to it and lash the two together.

“Hey,” Mason said, moving toward the fallen tree. “The wall’s leaning.”

Sure enough, we could see that the white lines of mortar were no longer straight, but curved and bowed around the impact of the pine.

I noticed another weird thing about the wall—a fat raccoon, perched up on it, fifty feet away. If that had been a real raccoon, it would have run the instant the wall shook.

Oakland’s voice shook me back to our task. “Let’s get the next one,” he shouted.

I nodded, staring at the raccoon for another few seconds. I’d seen the raccoon before, too.

Becky was also looking at the animal. Her eyes met mine. Tingles of panic were forming in my stomach, but I forced myself to turn back to the trees. There was too much to do.

We repeated the process, rocking a second tree—this one slightly thicker and with more branches—until it popped and fell. Unfortunately, our excitement at knocking the wall down was short-lived. The trunk hit the brick, continuing to bend the wall back, but it didn’t collapse.

“We could take down a third one,” someone suggested.

I looked at my watch. We’d already been working on the trees for almost half an hour. It was completely dark now, the only light coming from the glow of the low cold clouds.

Oakland gazed back at the other possible trees, including a big one that would easily crush the wall—if our cords could actually get it down without snapping. It was healthier than the two we’d felled.

“No,” he finally said. “Let’s get ’em stable and start going over.”

We rolled the second tree along the wall toward the first. We only had to move it about eight feet, but it was almost impossible, and I was no use at all with my bad arm. Pushing with my palms hurt far worse than pulling on the cords. It took at least ten minutes to roll it into position, and by the time we’d tied the two trunks together it seemed to have dropped another fifteen degrees.

Hector climbed to the top of the wall, carrying the third extension cord with him. He paused at the top and then turned back, worry on his face.

“There are animals over here,” he said, confused and nervous.

Oakland asked what he meant, but I immediately climbed up the logs to see for myself. Hector and I stood shoulder to shoulder on the top of the wall. Below us were a dozen animals—more raccoons and deer, and a hodgepodge of others: foxes, marmots, jackrabbits, and a porcupine. They waited around the wall, silent and still.

Beyond them was more forest.

“What the hell is this?” Hector breathed.

I pulled my paintball gun off my shoulder and fired three quick shots into the rabbit’s face, which knocked it back in an awkward jump. But it didn’t run. In the low light I couldn’t see if any damage had been done, but it was once again staring at us.

People behind us were screaming for answers, and Hector told them what was happening while I shot at a deer. I aimed for the eyes, trying to break whatever cameras were in there, but the deer hardly moved at all.

“Do they look like they’re going to attack?” Oakland asked, obviously annoyed.

“I don’t know,” I said over my shoulder. “What could a marmot do?”

I kept my eyes on the animals while I listened to the murmurs below. These robots looked for all the world like real animals except they were completely motionless.

“Okay,” Oakland shouted to the group. “Let’s get over this thing. Jump if you can—it’ll be faster—but don’t be an idiot and break your ankle. We ain’t carrying you.”

“What about the robots?” someone shouted.

“Hit ’em if they get close,” he answered. “That’s why we’re armed.”

Hector tied the cord to a thick branch of the fallen tree, and then took a deep breath and lowered himself down to the ground. I kept my gun trained on the robots, but none of them made any motion to attack. Not that my gun would have stopped them.

Oakland sent a few of the bigger guys over the wall next, and once ten were down, one of the Havoc kids tried swinging a shovel at a raccoon. It jumped out of the way amazingly fast but didn’t fight back.

I stayed on top of the wall, watching the rest of the Havocs go, then the Society. Finally the V’s climbed up the tree bridge. Becky stood on top of the wall now, and I climbed back down to help Carrie and Anna get Curtis up the logs. His fingers were curled tight, digging into my shoulder, and each breath sounded like an agonizing wheeze, as he tried to restrain himself from screaming in pain.

When he reached the top, he paused to catch his breath.

The students below were in a nervous cluster, staring outward at the endless sea of pines that continued before us. The animals had backed away, but were still in a loose semicircle around us.

We tied the cord around Curtis’s chest, under his arms. It wasn’t a good fix, and Carrie looked mortified as Anna, Becky, and I lowered him down. We couldn’t help but do it jerkily—Curtis was heavy—and he cried out when he finally hit the ground.

Carrie jumped down next, and then Anna and Becky.

On top of the wall, I turned for one final look back. I couldn’t see the school through the trees, and I wondered whether I’d ever see it in person again. Hopefully, I’d see it on the front page of the newspaper, with headlines about torture and imprisonment and I’d see Ms. Vaughn in an orange prison jumpsuit, being tried on dozens of counts of murder.

Below me, Oakland was already leading the group forward and into the forest. Guys with long-handled weapons—rakes and shovels and pruning hooks—walked ahead of the others, trying to shoo the robot animals away. Carrie was helping Curtis stay upright, and Becky was standing at the base of the wall, waiting for me.

I jumped. The ground was harder than I expected, and my shins stung on impact, but I was also filled with a sudden sense of elation. I didn’t know what lay ahead of us, but we had crossed the first obstacle.

This forest had sparser trees but thicker underbrush. We had to go slower now, fighting our way through the thick, dry bushes and grass. Becky and I were walking at the back now with Mason, Curtis hobbling up ahead of us. I felt isolated and vulnerable.

“This is bad,” she whispered. We had to look down to keep our footing, unable to properly keep a watchful eye on the forest.

Someone screamed, and everyone started talking at once. I couldn’t see what was going on, but they all started to run forward. Becky, Mason, and I jogged after them, slowed only by Curtis in front of us, who was staggering as quickly as he could.

“What happened?” I asked, trying to look ahead.

“Maybe they just got spooked,” Mason said.

“I have the gun,” Curtis wheezed.

I nodded, not taking my eyes off the people up front. “We might need it.”

Oakland’s voice wasn’t far, and I could hear him ordering the students to stay together and to keep moving.

“We’ll be okay,” I said, almost automatically. I didn’t know whether the assurance was more for them or for me.

People shouted up ahead. I tensed but quickly realized they were joyful cries. As we got closer we could see the fence, the chain link reflecting in the moonlight. We were there, and maybe the worst part was over. The animals were there, too, but everyone was ignoring them.