The rain in Los Angeles doesn't wash things clean. It just makes the dirt slicker.

I was sitting in my office on Sunset Boulevard, third floor above a noodle shop that smelled like garlic and regret, staring at a glass of bourbon that had seen better decades, when the client walked in.

She was small, maybe twenty-eight, with dark eyes that held too much knowledge for a face that young. She wore a man's overcoat that belonged to someone significantly larger, and she carried herself like someone who has learned that the world would not go easy on her.

"Mr. Kowalski?" she said. Her accent was Eastern European—Polish, maybe, or she had lived long enough in Asia to pick up the rhythm of a different language.

"That's what the sign says," I told her. "You're looking for someone. Everyone's looking for someone. The question is whether they can afford it."

"My name is Margaret Chen. I work at the Dodge Corporation—Data Analysis Division, Section 7."

I had heard of Dodge. Nobody in the private eye business had heard good things about Dodge, which is saying something because the things I had heard about other companies were generally worse.

"Data analysis," I said. "You count what?"

"Numbers. Patterns. Signals."

I set down my glass. "Signals. Like radio?"

"Like something that isn't radio but sounds like radio if you don't know better."

She placed a manila envelope on my desk. I opened it. Inside: pages of printed number sequences. Columns of integers, staggered, irregular but not random. The kind of pattern that makes your skin crawl if you spend enough time looking at it.

"Where did you get these?"

"My husband was a researcher at Dodge's Pacific Operations. He disappeared three months ago. Officially, he resigned. Unofficially, I found his notes." She tapped the envelope. "These are in his handwriting. They were part of a project called 'Wall.'"

"Wall."

"Wallfacer. The Wall Project. Top secret clearance. He was one of four researchers on the inner circle. The other three are either dead or promoted to positions that don't exist on any organizational chart. He was the fourth. And then he was gone."

I leaned back in my chair. The springs screamed. "What were the numbers?"

"An address. But not a street address. A celestial coordinate. And a sequence—prime numbers, Mr. Kowalski. They're sending prime numbers into space."

I should have taken the case. Something told me that I would, even though something else—something smarter than me—was telling me not to.

But I'm a detective. The not-taking-cases part was never going to happen.

"What do you need me to do?"

"Find him. Before they find me."

She left the envelope and disappeared into the Los Angeles rain, which was the same color as the rain in every city I had ever lived in: grey, guilty, and slightly alcoholic.

I opened the envelope fully and started reading.

The numbers formed a grid. Rows and columns of integers that meant nothing individually and everything collectively. I spent the next two nights cross-referencing them with public star catalogs from the Griffith Observatory and the Naval Observatory in Washington. By the morning of the third day, I had narrowed it down to a single point in the sky: a position between Earth and the constellation of Hercules.

A position where, according to every public catalog and private survey ever conducted, there was nothing.

Nothing except, apparently, something that knew how to count.

I called in a favor from an old war buddy named Morita, who worked as a clerk at the Pasadena Observatory. He was a good guy—quiet, meticulous, the kind of man who could stare at a spectrogram for eight hours and not blink.

"Dave," I said, sliding him a couple of bills, "can you run a spectrographic analysis on a specific coordinate and tell me what you see?"

He counted the bills without looking. "What coordinate?"

I gave him the numbers.

He looked at me then, really looked at me, with eyes that had spent twenty years looking at things most people would rather not see. "You're not playing around, huh?"

"Morita."

"I'll run it. But Dave—whatever you see out there, whatever the numbers say—it might be better if you didn't see it."

He ran it. His report, handwritten on onion-skin paper, was four pages long and contained approximately three hundred and forty-seven references to "anomalies," "irregularities," and "impossible readings."

The bottom line: the coordinate contained a mass. Not a visible mass—not a star, not a planet, not a cloud of gas. An invisible mass. An absence. Something that blocked out the background stars in a shape that Morita described as "teardrop-shaped, approximately three arc-seconds in angular diameter, and emitting—this is the part that made me not sleep for three days—a rhythmic modulation of the cosmic microwave background radiation that matches, to seven significant figures, a prime number sequence."

I showed the report to Margaret when she came back. She read it in silence, her face doing nothing, and when she finished, she said one word:

"Thank you."

"Thank you for what?"

"For confirming what you don't believe. It's rarer than people think."

She left again. I sat in my office and stared at the report. I was a thirty-five-year-old veteran with a damaged right ear, a bad leg, and a collection of problems that therapy couldn't fix. I was not a man who dealt in cosmic coordinates and prime-number signals. I was a man who dealt in missing persons, cheating spouses, and occasionally—when the paying was good—industrial espionage.

This was above my pay grade. This was above everyone's pay grade.

I was about to tell Margaret that I was quitting—the case, the whole ridiculous enterprise—when the man in the grey suit walked in.

He was maybe fifty, with a face you couldn't quite remember ten seconds after he left the room. That was his most distinctive feature: unmemorability. Not plain, exactly, but engineered. His haircut, his clothes, his mannerisms were all calibrated to slip through human memory like water through a sieve.

"Mr. Kowalski," he said. His voice was pleasant and completely forgettable. "I represent a private organization interested in your recent activities."

"I don't represent anyone."

"That's what we expected you to say. We're not here to offer you a job, Mr. Kowalski. We're here to inform you that you are currently investigating a project designated WALLFACER, which is classified at the highest level and does not, for legal and practical purposes, exist."

"Then how do you know about it?"

The man smiled. It was a practiced smile—reassuring but empty. "We know everything, Mr. Kowalski. We know about Margaret Chen. We know about Morita at Pasadena. We know you've been to the Griffith Observatory twice and the Public Library's microfilm room once. We know all of this because your activities have been monitored since the moment you accepted Ms. Chen's retainer."

"Who are you?"

"A department that doesn't exist. We're part of an effort that predates this government. And we're telling you, as a courtesy, to stop."

"Why? What are they hiding?"

The man's smile didn't change. "Mr. Kowalski, imagine that you discover a fact so devastating, so irreversibly world-shattering, that the only rational response is to bury it so deep that even the people who dug the hole forget why it's there. That is our mission. To bury facts."

He stood up. He looked at me with eyes that I already couldn't quite remember.

"You are close, Mr. Kowalski. Closer than anyone in your position should be. I would advise you to stop now. For your own sake."

He left. I sat in my chair for a long time. The bourbon was gone. The rain continued. And somewhere in the sky above Los Angeles, something invisible was counting primes into the void.

I made my decision that night.

I would not stop. Not because I was brave—I wasn't. Not because I believed I could make a difference—I didn't. I stopped because I was a detective, and the moment you start investigating something, stopping is not an option. It's like trying to un-see something you've seen. Impossible.

I called Margaret. "Meet me at the newspaper. The Times. I've got a story to run."

"The Wall Project?"

"The Wall Project."

"I'll bring the data."

We met at the Times building at 2 AM. The night editor was a drunk named O'Brien who owed me a favor from the war, and I used that favor to get the story printed in the morning edition: every number, every coordinate, every prime-number sequence, and a theory—that a classified government project was deliberately broadcasting a celestial coordinate into space, potentially marking Earth for something that was already on its way.

The story ran. At 6 AM, the city woke up to it.

By noon, the story was gone. Not retracted—not corrected. Gone. Every copy of the paper that contained it was recalled by order of the Governor's office. O'Brien was transferred to the obituary section, where he would remain for the rest of his career.

And Margaret Chen disappeared.

I found her apartment empty. Her belongings gone. Her landline disconnected. The landlord told me she had left two days after I saw her, with nothing but a small suitcase and a box of books.

I went to Pasadena. Morita wasn't there. His desk was empty, his locker unlocked and bare. His supervisor told me he had resigned without notice. I checked the social security database. David Morita—no record. Joseph Morita—no record.

He had been erased.

I went back to my office on Sunset Boulevard. The noodle shop below was still smelling like garlic and regret. My glass of bourbon was still half-full on the desk.

Three months passed. I didn't take another case during that time. I sat in my office every night, staring at the ceiling, wondering if I had made the right decision. Had I saved the world by publishing that story? Had I doomed it? Or had I done nothing at all—just a small, temporary ripple in an ocean that didn't care?

Then the package arrived.

No return address. No postage mark. Just delivered, hand-to-hand, by someone I never saw. Inside: a single photograph.

Me. Taken last night, from the street below, through my office window. On the back, in handwriting I couldn't identify: "We know you know."

I walked to the window and looked out at Los Angeles. The neon signs flickered—pink, blue, yellow—like some enormous circuit board, and for one moment, just one moment, the pattern of the lights looked like numbers.

Prime numbers.

I closed the window. I locked the door. I sat down at my desk. And I waited.