It was raining in Los Angeles. Not the kind of rain you see in movies—the dramatic kind that washes everything clean. This was the other kind. The kind that just makes everything worse. It had been raining for three days. The streets were slick with oil and water and the kind of grime that no amount of rain can wash away.

I was sitting in my car, parked on a street I can't remember the name of, watching a detective I can't forget. His name was Malone. Detective "The Vulture" Malone, because that's what the other cops called him behind his back. He smelled like cheap cologne and cheaper decisions, and his eyes had that look that men get when they've seen too much and understood too little.

He got in my car without knocking. The door opened, he sat down, and the smell hit me—cheap cologne, sweat, and something else. Something metallic. Like blood that's been washed off but not really.

"Jack," he said. "I need your help."

I looked at him. I was twenty-eight, out of the army, out of ideas, and out of places to go. I didn't have a job, I didn't have a woman, and I didn't have a reason to get up in the morning. So helping Malone sounded about as exciting as anything else on my schedule.

"What do you need?" I asked.

He leaned forward, and I could see his eyes better. They were pale blue, almost grey, and they had that hungry look that men get when they want something they have no right to want.

"There's something underground," he said. "In the old part of town. A group of people. They call themselves the Root Keepers. They've been extracting something from the roots of old trees—roots that go down deep, deeper than any tree should go. They make a drug from it. A bad drug. The kind that makes people see things that aren't there."

"Sounds like my kind of thing," I said.

"It's not a joke, Mercer."

"I'm joking. It's a habit."

He didn't smile. Nobody ever smiled with Malone. "I need you to find them. I need you to lead my men to them. And I need you to do it tonight."

"Why me?"

"Because you're invisible. You're nobody. You walk down the street and people look right through you. That's useful, sometimes."

I looked out the window at the rain. He was right. I was invisible. I'd been invisible since I came back from the war, since I couldn't sleep without hearing things that weren't there, since I couldn't look at a crowd without feeling like I was drowning.

"Who's paying me?" I asked.

Malone smiled. It was not a kind smile. "You'll pay me. In favors. And I collect favors. That's what I do."

I said yes. Not because I wanted to. Because I had nothing else to do.

Her name was Evelyn Cross. I met her that night, in a bar on Sunset that had neon lights and a piano player who couldn't play and a bartender who didn't ask questions. She was sitting at the counter, wearing a red dress that cost more than my car and a smile that cost more than that.

She was thirty, maybe thirty-one, with hair like dark honey and eyes that could cut glass. She looked at me and smiled, and I knew immediately that she was trouble. The kind of trouble you invite in and then can't get rid of.

"I'm Evelyn," she said.

"I know who you are," I said.

"Then you know I don't give my number to strangers."

"I'm not a stranger. I'm Jack Mercer. I'm nobody. That's different."

She laughed. It was a nice sound, like ice in a glass. "You're funny, Jack Mercer. I like funny."

She was my guide to the underground. Not the literal underground—the metaphorical one. The one beneath Los Angeles, beneath the streets and the buildings and the people, where the real things happened. The things that didn't make the newspapers.

She knew the Root Keepers. Or she knew people who knew them. She moved through this world the way a fish moves through water—effortlessly, without thinking about it, like it was the only thing she'd ever known.

"They're not drug dealers," she said, three nights later, in the back of my car, parked outside an old warehouse on the edge of downtown. "They're just people. People who found something underground and decided to use it instead of running from it."

"What did they find?"

She looked at me, and for a second, her smile faded. "A root. A big one. Goes down deeper than anyone can tell. And from it, they extract something. Something that makes you see things. Real things, maybe. Or things that feel real. I don't know the difference anymore."

I got out of the car. I walked to the warehouse. I found the door. I went in.

The basement was bigger than I expected. The walls were lined with shelves, and the shelves were lined with jars, and the jars contained roots—thick, dark, twisted roots that looked like they'd been pulled from the bottom of the world. There were maybe eight people down there, moving between the shelves, cutting the roots, drying them, grinding them into powder.

They didn't look like drug dealers. They looked like people who had nothing left and were making something out of nothing. An old man with shaking hands. A young woman with tired eyes. A boy, maybe sixteen, who looked too young to be doing whatever it was he was doing.

I found Evelyn waiting for me outside.

"Well?" she said.

"They're just people."

"I told you."

I called Malone. I told him where to find them. I gave him the address, the time, the number of people I'd seen. I stood on the sidewalk and watched him pull up in an unmarked car with three other men, and I felt something in my chest that I couldn't name.

Guilt? No. Guilt implies you made a choice. I hadn't chosen. I'd been pushed. Pushed by Malone, pushed by Evelyn, pushed by the rain and the empty apartment and the silence that followed me everywhere.

They went in at midnight. I watched from the car.

What happened next, I don't know for sure. Different people tell different stories. Malone says the Root Keepers attacked them. The Root Keepers say Malone attacked them. Evelyn says nobody attacked anybody—she says it was the drug, the powder, the roots, that made everyone see things that weren't there.

Here's what I think happened.

Malone went in with his men. He found the jars. He found the roots. He told his men to bag everything. And then someone—maybe an old man with shaking hands, maybe the young woman with tired eyes—opened a jar and inhaled the powder.

And saw things.

Or maybe they all inhaled it. Maybe Malone did too. Maybe that's why he started screaming. Maybe that's why his men started screaming. Maybe that's why the young woman started screaming.

I don't know. I was in the car, watching the rain hit the windshield, listening to the piano player in the bar across the street play a song I can't remember.

When I finally got out of the car, the warehouse was in chaos. People were running. Jars were broken. Powder was everywhere, covering the sidewalk like black snow. Malone was on his knees, screaming at something that wasn't there.

And then he saw me.

"Mercer!" he yelled. "You set me up! You led me into a trap!"

I didn't answer. I turned and walked away.

Evelyn found me two blocks away. She was holding a bag—small, leather, the kind women use for makeup. But it was heavy. I could see the way it pulled on her arm.

"Come with me," she said.

"No."

"Jack, please."

"I don't do 'please' anymore."

She looked at me for a long time. Then she said: "You did good, Jack Mercer. You led the vulture to his own trap. He's done. His men are done. The Root Keepers are scattered. And I have what I came for."

"The powder?"

"The root. The big one. The one that goes down deeper than anyone can tell."

She got in a car—a nice car, not mine, not Malone's—and drove away. I watched her go. I watched the taillights disappear into the rain.

And then I went home. Or somewhere that was home. A room, a bed, a window that looked out on a wall. I sat on the bed and I smoked a cigarette and I listened to the rain.

Three days later, I was arrested.

Not for what happened at the warehouse. For something else. Something old. An outstanding warrant from a charge I'd forgotten about. A misdemeanor. A stupid thing I'd done in a bar in Long Beach six months ago. I'd forgotten about it because I forget a lot of things.

They put me in a cell. Small, concrete, with a toilet that didn't work and a window that looked out on nothing. I sat on the bunk and I listened to the sounds of the jail—doors slamming, men shouting, keys jangling—and I thought about Evelyn, and Malone, and the Root Keepers, and the big root that went down deeper than anyone could tell.

I thought about the powder. I'd inhaled some of it, just a little, in that warehouse. Just a whiff. And for a second—just a second—I'd seen something. Not a vision. Not a hallucination. Just a feeling. A feeling so strong it was like seeing. A feeling of something vast and patient and ancient, deep underground, waiting.

Waiting for what, I don't know.

Maybe for nobody. Maybe for everybody.

I sat in my cell and I smoked a cigarette—contraband, passed from the man in the next cell, a guy named Ray who'd been in and out of jail so many times he'd lost count—and I waited.

They'll keep me here for a while. Six months, maybe a year. I'll get bored. I'll get angry. I'll get quiet. And then I'll get used to it. That's what you do in this country. You get used to things.

But sometimes, late at night, when the jail is quiet and the lights are dim and the other men are sleeping, I close my eyes and I listen. And I hear something. A hum. A low hum. Coming from somewhere far away. Or somewhere very close.

Underground.

Beneath the concrete. Beneath the streets. Beneath everything.

Something is down there. Something old and patient and vast. And it's waiting.

I don't know for what. But I know it's waiting.

And I know, with a certainty that scares me, that when it's ready, it will rise.

The rain keeps falling in Los Angeles. It always does. It falls on the jail, on the warehouse, on the street where Evelyn drove away, on the grave where Malone will eventually end up. It falls on everything. And it washes nothing clean.