We sped off the pier. My heart thundered and my skin felt like glue. I stared out the passenger window as a bitter taste rose in my throat. The body was still and crumpled, cast aside like garbage.

"Do you recognize him?" Rachel asked, weaving through the stopped traffic and across the street.

"No." A young Black guy with wire-rimmed glasses, wearing a sweater with straps and buckles. "That’s not a sweater," I said, feeling faint. "That’s a straightjacket."

"At least it’s not a bomb," she said.

I swallowed. "PJ put him in a straightjacket and cut his throat."

"He must've been an active," Rachel said. "PJ’s pulling his strength together." She punched the horn. "Which way did he go?"

"I don’t know, I--" The chirrup sounded again, and I saw a flash of white to the south. "There! To the right."

She yanked the wheel. "Got him."

The car fishtailed, then we shot down the avenue. Buildings blurred, pedestrians shouted. My hand ached, and I clenched and unclenched my fingers.

Rachel sped past two cabs and scraped a third one. I moaned and she leaned on her horn and burned through a red light.

"You can't drive!" I yelled. "Remember? Let's try to stay alive long enough for PJ to kill us, okay?"

"I like the long-term thinking," she said, her attention never wavering from the road in front of her.

"How'd he find us?" I asked.

"That's the easy part," she told me. "The question is, where's he leading us?"

The ambulance swerved in the traffic, a half-block ahead.

Rachel swerved, too, and I steadied myself on the dashboard and said, "Where are the cops?"

They’d been all over the streets after the bombings, but none were in sight at the moment. Before Rachel could answer, PJ’s ambulance jogged sharply around a double-parked van. Rachel swore and followed--just in time to see the ambulance jerk around a corner, the back doors swinging wildly opened and closed again.

A second later, Rachel slammed the brakes and I braced myself against the dash and saw the lump in the road, the reason she’d stopped: another body. An older woman, her straightjacket stained with blood.

A muscle twitched in Rachel’s jaw. She gunned the engine for three blocks, four blocks, following the bleat of the siren. Then the avenue split at 14thor 24thstreet--well, it ended with a ‘4’, I didn't see the first number--into a wide intersection, a sudden expanse of space with crosswalks angling in every direction, and traffic islands dotted with pine bushes in heavy planters.

Two police cars flashed yellow and red, stopped by the curb. One of them was surrounded by seven or eight people--a cross-section of New Park, any given streetcorner--rocking the car while a bunch of businessmen methodically kicked a cop lying in the street, his face a pulp of blood and flesh.

"The--there!" Jittery urgency rose in me at the sight; I needed to do something, I needed to kep those people from beating someone to death. "Stop, stop the car!"

The car didn't slow. Rachel gave the tableau a rippling glance and said, "PJ’s not using bombs anymore. He’s making them rip each other apart with bare hands."

"Stop the fucking car!"

She sped through the intersection, following the ambulance southward. A gunshot rang out as I was swearing at her, and I caught my breath. Then a volley of gunshots. I couldn't tell from which direction.

A siren sounded and a police car slowed at the next intersection, fifty feet away. A peppermill bounced off the black-and-white's windshield and a dozen people boiled from a café and surged into the road. Two cops ran toward the café, guns in hand.

I reached for the door handle, but Rachel hit the gas and said, "No. Stay."

"Goddamit, Rachel, people are dying!"

"Keep your ass in that seat," she snapped.

Another volley of gunfire sounded, and she drove onto the sidewalk to avoid the mob, clipped a row of newspaper racks, and slammed back off the curb.

The car bounced so hard that my teeth snapped shut. We sped down the next block, then Rachel turned the wrong way down a one-way street and gritted her teeth until the end of the block while I half-closed my eyes, wiping my palms on my jeans. She was right. I knew she was right. We needed to stop PJ. That was the only thing that mattered.

"PJ's sending them after cops," I said. "He's making people kill cops."

"Yeah, he brought cops onto the street with the bombings," she told me. "Now he's making mobs, aiming them at cops. At armed targets with authoritarian tendencies who'll hit back a hundred times harder. He wants this to escalate."

I caught sight of the ambulance, abandoned in the middle of a side-street not far from Broadway. "There!"

Rachel swung into the street and parked at a crazy angle. We left our car and Rachel unsnapped her holster. Ten feet from the ambulance, she nodded to me and I knew what she wanted. I freed the orbs. Two surveyed the street from above us while the third shot toward the ambulance.

"There's something in back," I told her, deciphering the orb's images. "Another body."

It was a pretty, plump girl in her twenties lying on the floor, dressed office-casual beneath the straightjacket, her throat slit. Even in death, her face gave the impression that she’d known how to smile, that she’d liked smiling.

I steadied myself against the ambulance. Like Dewitt. The gift of happiness. I’d never see him smile again.

Rachel brushed the girl’s hair back. "She's an active."

Pointed ears. The girl had perfect little pointed ears.

"She’s an elf." I choked on a sob. "Oh my god, omigod, he killed an elf--"

"Lark."

"What are we going to do? We can't stop him, we can't--"

"Lark!" Rachel snapped, her voice harsh. "Take a breath."

"An elf," I said, wiping my eyes. "Okay. I’m okay."

She looked past me, and took a sharp breath. "Goddamn."

Fifty students poured from a school across the street. Young and preppy and rolling toward us like an avalanche. Too silent for a normal crowd, their eyes blank and narcotic.

The orbs hovered close and Rachel said, "Wait. They’re not after us."

She grabbed my hand as the wave of students hit. Except they didn’t hit--they parted around us and stalked away.

"They’re after cops." She dragged me back toward the car. "Let’s go."

"I still don't get it. Why cops?"

"Because explosive vests are expensive, and suicide by cop is cheap."

"Yeah, but what does he want with--"

A fire engine screamed through a nearby intersection, and we slid into our car and Rachel punched forward, ignoring the shouts of the drivers she’d trapped behind her, scraping past the ambulance with a shriek of metal against metal.

"Where are we going?" I asked.

"Looking for the back door of that school."

"You think PJ's inside?"

"Only one way to find out," she said.

The wheels squealed around the corner. Car alarms punctured the air. Gunfire sounded and glass shattered. Rachel turned again, onto a narrow street behind the school, made narrower by the row of parked cars.

She jerked to a halt behind a stopped dump-truck that blocked her way.

"Great," she muttered.

"Go around," I said.

Then a crash sounded, the car jerked, and the roof buckled overhead. Pressing down toward us like a vise.