“What are you doing?”

I spin around. Coral has emerged from the trees.

“What are you doing?” I turn back to the tree and try again, picking a different grip this time. No time, no time, no time.

“You said to cover for you,” she says.

“Keep your voice down,” I whisper sharply. I’m surprised that she actually cared enough to follow me. “I have to get over the wall.”

“And do what?”

I try a third time—managing to skim the branches above my head with my fingertips—before my legs give out and I’m forced to jump back to the ground. My fourth attempt is worse than the first three. I’m losing control, I’m not thinking straight.

“Lena. What are you planning to do?” Coral repeats.

I spin around to look at her. “Give me a boost,” I whisper.

“A what?”

“Come on.” The panic is creeping into my voice. If Raven and the others haven’t already crossed, they’ll be trying to any second. They’re counting on me.

Coral must hear the change in my tone, because she doesn’t ask any more questions. She laces her fingers together and squats so I can wedge my foot in the cradle formed by her hands. Then she lifts me, grunting, and I shoot upward and manage to pull myself into the branches, which fan out from the trunk like the spokes of an umbrella laid bare. One branch extends almost all the way to the wall. I lean down onto my stomach, pressing myself flat against the bark, scooting forward like an inchworm.

The branch begins to sink under my weight. Another foot or so, and it begins to sway. I can’t go any farther. As the branch sinks, the distance between my position and the top of the wall increases; any farther, and I’ll have no chance of making it over.

I take a deep breath and move into a crouch, keeping my hands tightly wrapped around the branch, which is swaying lightly underneath me. There’s no time to worry or debate. I spring up and toward the wall and the branch moves with me, like a springboard, as my weight is released.

For a second I’m airborne, weightless. Then the wall’s concrete edge drives hard into my stomach, knocking the wind out of me. I just manage to hook both my arms over the wall and pull myself over, dropping onto the elevated pathway that the guards walk during their patrol. I pause in the shadows to get control of my breathing.

But I can’t rest for very long. I hear a sudden eruption of sound: guards calling to one another, and heavy footsteps jogging in my direction. They’ll be on me in no time, and I’ll have lost my chance.

I stand and sprint toward the alarm tower.

“Hey! Hey, stop!”

Shapes materialize from the dark: one, two, three guards, all men, moonlight on metal. Guns.

The first shot dings off one of the steel supports of the alarm tower. I throw myself into the small, open-air tower as more shots rattle the air. My vision is tunneling and everything sounds distant. Disjointed images flash in my head, like stills from different movies: Shots. Firecrackers. Screaming. Children on the beach.

And then all I can see is the small lever, illuminated from above by a single bulb encased in metal wiring: EMERGENCY ALARM.

Time seems to wind down. My arm looks like someone else’s, floating toward the lever, agonizingly slow. The lever is in my hand: the metal is surprisingly cold. Slowly, slowly, slowly, the hand grips; the arm pushes.

Another shot, the ring of metal all around me: a fine, high vibration.

Then, all at once, the night is pierced with a shrill, wailing cry, and time shudders back to normal speed. The sound is so tremendous, I can feel it in my teeth. An enormous bulb at the top of the alarm tower lights up and begins turning, sending a sweep of red across the city.

There are arms reaching for me through the metal scaffolding: spider arms, huge and hairy. One of the guards grabs my wrist. I reach out and wrap a hand around the back of his neck, pull him suddenly forward, and he collides forehead-first with one of the steel supports. His grip on me releases as he staggers backward, cursing.

“Bitch!”

I burst free from the tower. Two steps, over the wall, and I’ll be fine, I’ll be free. Bram and Coral will be waiting in the trees . . . we’ll lose the guards in the darkness and the shadows. . . .

I can make it. . . .

That’s when Coral comes over the wall. I’m so startled, I stop running. This isn’t protocol. Before I have time to ask her what she’s doing, an arm is wrapped around my waist, hauling me backward. I smell leather and feel hot breath on my neck. Instincts take over; I shove my elbow back into the guard’s stomach, but he doesn’t release me.

“Hold still,” he snarls.

Everything is short bursts: Someone is screaming, and a hand is around my throat. Coral is in front of me, pale and lovely, hair streaming behind her, arm raised—a vision.

She’s holding a rock.

Her arm pinwheels, a graceful, pale arc, and I think, She’s going to kill me.

Then the guard grunts, and the arm around my waist goes slack, and the hand releases as he crumples to the ground.

But now they are appearing from everywhere. The alarm is still screaming, and at intervals the scene is lit up in red: two guards on our left; two guards on our right. Three guards, shoulder to shoulder, pressed against the wall, blocking our path to the other side.

Sweep: The light cuts over us again, illuminating a metal stairway behind us, stretching down into the narrow chasm of city streets.

“This way,” I pant. I reach out and tug Coral down the stairs. This move was unexpected, and it takes the guards a moment to react. By the time they reach the stairway, Coral and I have hit the street. Any second more guards will arrive, summoned by the alarm. But if we can find a dark corner . . . Somewhere to hide and wait it out . . .

Only a few streetlamps are still lit. The streets are dark. A smattering of gunfire rings out, but it’s clear the guards are firing at random.

We make a right, then a left, then another right. Footsteps drum toward us. More patrols. I hesitate, wondering whether we should go back the way we came. Coral puts a hand on my arm and draws me toward a thick triangle of shadow: a recessed doorway, scented with cat urine and cigarette smoke and half-concealed behind a pillared entry. We crouch in the shadows. A minute later, a blur of bodies goes by, a buzz of walkie-talkie voices and heavy breathing.

“Alarm’s still going. Position twenty-four is saying there’s been a breach.”

“We’re waiting for backup to start the sweep.”

As soon as they pass, I turn to Coral.

“What the hell were you doing?” I say. “Why did you follow me?”

“You said I was supposed to back you up,” she says. “I got freaked when I heard the alarm. I thought you must be in trouble.”

“What about Bram?” I say.

Coral shakes her head. “I don’t know.”

“You shouldn’t have risked it,” I say sharply. Then I add, “Thank you.”

I start to climb to my feet, but Coral draws me back.

“Wait,” she whispers, and brings her fingers to her lips. Then I hear it: more footsteps, moving in the opposite direction. Two figures come into view, moving fast.

One of them, a man, is saying, “I don’t know how you lived with that filth for so long. . . . I’m telling you, I couldn’t have done it.”

“It wasn’t easy.” The second one is a woman. I think her voice sounds familiar.

As soon as they pass out of view, Coral nudges me. We need to move away from the area, which will soon be crawling with patrols; they’ll probably turn on the streetlamps, too, so their search will be easier.

We need to head south. Then we’ll be able to cross back into the camp.

We move quickly, in silence, sticking close to the buildings, where we can easily duck into alleys and doorways. I’m filled with the same suffocating fear I felt when Julian and I escaped through the tunnels and had to make our way through the underground.

Abruptly, all the streetlamps come on at once. It’s as though the shadows were an ocean, and the tide has gone out, leaving a barren, ridged landscape of empty streets. Instinctively, Coral and I duck instinctively into a darkened doorway.

“Shit,” she mutters.

“I was afraid this would happen,” I whisper. “We’ll have to stick to the alleys. We’ll stick to the darkest places we can find.”

Coral nods.

We move like rats: We scamper from shadow to shadow, hiding in the small spaces: in the alleys and the cracks, the darkened doorways and behind the Dumpsters. Twice more, we hear patrols approaching us and have to duck into the shadows, until the buzz of static walkie-talkies, and the rhythm of footsteps, is gone.

The city changes. Soon, the buildings thin out. At last the sound of the alarm, still wailing, is no more than a distant cry, and we sink gratefully back into an area where the streetlamps are dark. The moon above us is high and bloated. The apartments on either side of us have the empty, forlorn look of children separated from their parents. I wonder how far we are from the river, whether Raven and the others managed to explode the dam, whether we would have heard it. I think of Julian and feel a twist of anxiety and also regret. I’ve been hard on him. He’s doing his best.

“Lena.” Coral stops and points. We’re moving past a park; at its center is a sunken amphitheater. For a second, confusedly, I have the impression of dark oil, shimmering between its stone seats; the moon is shining down onto a slick black surface.

Then I realize: water.

Half the theater is flooded. A coating of scattered leaves is swirling across its surface, disturbing the watery reflections of the moon, stars, and trees. It’s strangely beautiful. I take an unconscious step forward, onto the grass, which squelches under my feet. Mud bubbles up beneath my shoes.

Pippa was right. The dam must have forced the water over the riverbanks and flooded some of the downtown areas. That must mean we’re in one of the neighborhoods that was evacuated after the protests.

“Let’s get to the wall,” I say. “We shouldn’t have any trouble crossing.”

We continue skirting the periphery of the park. The silence around us is deep, complete, and reassuring. I’m starting to feel good. We’ve made it. We did what we were supposed to do—with any luck, the rest of our plan went off too.

At one corner of the park is a small stone rotunda, surrounded by a fringe of dark trees. If it weren’t for the single, old-fashioned lantern burning on the corner, I would have missed the girl sitting on one of its stone benches. Her head is dropped between her knees, but I recognize her long, streaked hair and her mud-caked purple sneakers. Lu.

Coral sees her at the same time I do. “Isn’t that . . . ?” she starts to ask, but I’m already breaking into a run.

“Lu!” I cry out.

She looks up, startled. She must not recognize me immediately; for a second her face is vivid white, frightened. I drop into a squat in front of her, put my hands on her shoulders.

“Are you all right?” I say breathlessly. “Where are the others? Did something happen?”

“I . . .” She trails off and shakes her head.