If Ben had sprained an ankle or twisted a knee, he might have hobbled downhill instead of making the steep climb back to my house; he might have knocked on someone's door for help; he might be limping home on his own. I told myself, sure, that had to be it. Ten-year-old boys don't simply vanish.

When I reached the street that follows the drainage below my house, I parked and got out. The light was fading faster and the murk made it difficult to see. I called for him.

Ben?

If Ben had come downhill, he would have passed beside one of three houses. No one was home at the first two, but a housekeeper answered at the third. She let me look in their backyard, but watched me from the windows as if I might steal the pool toys. Nothing. I boosted myself to see over a cinder-block wall into the neighboring yards, but he wasn't there, either. I called him again.

Ben!

I went back to my car. It was all too easy and way too likely that we would miss each other; as I drove along one street, Ben might turn down another. By the time I was on that street, he could reappear behind me, but I didn't know what else to do.

Twice I waved down passing security patrols to ask if they had seen a boy matching Ben's description. Neither had, but they took my name and number, and offered to call if they found him.

I drove faster, trying to cover as much ground as possible before the sun set. I crossed and recrossed the same streets, winding through the canyon as if it was me who was lost and not Ben. The streets were brighter the higher I climbed, but a chill haunted the shadows. Ben was wearing a sweatshirt over jeans. It didn't seem enough.

When I reached home, I called out again as I let myself in, but still got no answer. The note that I left was untouched, and the message counter read zero.

I phoned the dispatch offices of the private security firms that service the canyon, including the company that owned the two cars I had already spoken to. Their cars prowled the canyons every day around the clock, and the companies' signs were posted as a warning to burglars in front of almost every house. Welcome to life in the city. I explained that a child was missing in the area and gave them Ben's description. Even though I wasn't a subscriber, they were happy to help.

When I put down the phone, I heard the front door open and felt a spike of relief so sharp that it was painful.

Ben!

It's me.

Lucy came into the living room. She was wearing a black business suit over a cream top, but she was carrying the suit jacket; her pants were wrinkled from so long in the car. She was clearly tired, but she made a weak smile.