Then I heard footsteps in the hallway. Someone knocked on the bathroom door, waited, then knocked again. I closed the receipt book in a hurry. The footsteps went back toward the main room. They were careful here. Nothing incriminating. It was bare; it was spare. As I was putting the book back where I found it, I saw a matchbook jammed in a corner. I pulled it out. Printed in red and green, it was from a motel called El Nido in the border town of Mexicali. Maybe that was the border Cathy Vega had come through. I put it in my suit pocket.

The main room was still dark and silent except for Guerrero’s voice, which had lost none of its strength or urgency. At the end of the hall was the outline of another door, which I assumed had to lead to the backyard visible from the roof of the building across the street. I had also noticed that a small boxy structure stood behind Casa Guatemala. That had to be where they kept the good stuff. A bomb factory. A secret press.

As noiselessly as I could, I opened that door. It was almost completely dark outside now. The back lot deadened against a hill covered with ivy. At the top of the hill, a hundred feet or so above the yard, stood an apartment building. I heard radios and the laughter of children. I slipped out into the dark. The lot was covered with cracked asphalt as though it had once been the parking lot when the building was a business. The box seemed a recent addition, quickly built of cinder blocks with a tin roof.

An old motorcycle, a Honda, stood in the middle of the lot with an oil leak spreading under its tank. A few pots of tired geraniums lined a tall fence that enclosed the lot. The smell of eucalyptus and jasmine blew across the yard. The whine of cars from Sunset sounded distant, but maybe that was because the blood was starting to pound in my head.

The shed door was padlocked. A new padlock. I pulled at it once, but it wouldn’t give. Next to the door was a window, but it was covered by a heavy dark curtain. Checking on the west side of the building, I saw the same fabric in the window of that wall. I pushed myself into the shadows and crept toward the back of the shed. It was the same rudimentary layout, a window in the center of the wall. I moved slowly along the back wall, inching toward that window. I could hear my breathing jagged, almost breathless—as I tried not to make any noise in my high heels, the metal tips hitting the asphalt.