"You just hire a replacement for Tad?"

I turned and watched Tony come in from outside through the open bay doors, where he'd evidently been lurking and watching the byplay between the boy and me. Tony was good at that-it was his job.

His black hair was slicked back and tied into a short ponytail and he was clean-shaven. His right ear, I noticed, was pierced four times and held three small hoops and a diamond stud. He'd added two since last time I'd seen him. In a hooded sweatshirt unzipped to display a thin tee that showed the results of all the hours he spent in a gym, he looked like a recruitment poster for one of the local Hispanic gangs.

"We're negotiating," I said. "Just temporary so far. Are you working?"

"Nope. They gave me the day off for good behavior." He was still focused on my new employee, though, because he said, "I've seen him around the past few days. He seems okay-runaway maybe." Okay meant no drugs or violence, the last was reassuring.

When I started working at the garage about nine years ago, Tony had been running a little pawnshop around the corner. Since it had the nearest soft drink machine, I saw him fairly often. After a while the pawnshop passed on to different hands. I didn't think much of it until I smelled him standing on a street corner with a sign that said WILL WORK FOR FOOD.

I say smelled him, because the hollow-eyed kid holding the sign didn't look much like the low-key, cheerful, middle-aged man who had run the pawnshop. Startled, I'd greeted him by the name I'd known him by. The kid just looked at me like I was crazy, but the next morning Tony was waiting at my shop. That's when he told me what he did for a living-I hadn't even known a place the size of the Tri-Cities would have undercover cops.

He'd started dropping by the shop every once in a while, after that. At first he'd come in a new guise each time. The Tri-Cities aren't that big, and my garage is on the edge of an area that's about as close as Kennewick comes to having a high-crime district. So it was possible he just came by when he was assigned to the area, but I soon decided the real reason was he was bothered I'd recognized him. I could hardly tell him I'd just smelled him, could I?

His mother was Italian and his father Venezuelan, and the genetic mix had given him features and skin tone that allowed him to pass as anything from Mexican to African-American. He could still pass for eighteen when he needed to, though he must be several years older than me-thirty-three or so. He spoke Spanish fluently and could use a half dozen different accents to flavor his English.

All of those attributes had led him to undercover work, but what really made him good was his body language. He could stride with the hip-swaggering walk common to handsome young Hispanic males, or shuffle around with the nervous energy of a drug addict.

After a while, he accepted I could see through disguises that fooled his boss and, he claimed, his own mother, but by then we were friends. He continued to drop in for a cup of coffee or hot chocolate and a friendly chat when he was around.

"You look very young and macho," I said. "Are the earrings a new look for KPD? Pasco police have two earrings, so Kennewick cops must have four?"

He grinned at me, and it made him look both older and more innocent. "I've been working in Seattle for the past few months," he said. "I've got a new tattoo, too. Fortunately for me it is somewhere my mother will never see it."

Tony claimed to live in terror of his mother. I'd never met her myself, but he smelled of happiness not fear when he talked of her, so I knew she couldn't be the harridan he described.

"What brings you to darken my door?" I asked.

"I came to see if you'd look at a car for a friend of mine," he said.

"Vee-Dub?"

"Buick."

My eyebrows climbed in surprise. "I'll take a look, but I'm not set up for American cars-I don't have the computers. He should take it somewhere they know Buicks."

" She's taken it to three different mechanics-replaced the oxygen sensor, spark plugs, and who knows what else. It's still not right. The last guy told her she needed a new engine, which he could do for twice what the car's worth. She doesn't have much money, but she needs the car."

"I won't charge her for looking, and if I can't fix it, I'll tell her so." I had a sudden thought, brought on by the edge of anger I heard in his voice when he talked about her problems. "Is this your lady?"

"She's not my lady," he protested unconvincingly.

For the past three years he'd had his eye on one of the police dispatchers, a widow with a slew of kids. He'd never done anything about it because he loved his job-and his job, he'd said wistfully, was not conducive to dating, marriage, and kids.

"Tell her to bring it by. If she can leave it for a day or two, I'll see if Zee will come by and take a look at it." Zee, my former boss, had retired when he sold me the place, but he'd come out once in a while to "keep his hand in." He knew more about cars and what made them run than a team of Detroit engineers.

"Thanks, Mercy. You're aces." He checked his watch. "I've got to go."

I waved him off, then went back to the transmission. The car cooperated, as they seldom do, so it didn't take me long. By the time my new help emerged clean and garbed in an old pair of Tad's coveralls, I was starting to put the rest of the car back together. Even the coveralls wouldn't be warm enough outside, but in the shop, with my big space heater going, he should be all right.

He was quick and efficient-he'd obviously spent a few hours under the hood of a car. He didn't stand around watching, but handed me parts before I asked, playing the part of a tool monkey as though it was an accustomed role. Either he was naturally reticent or had learned how to keep his mouth shut because we worked together for a couple of hours mostly in silence. We finished the first car and started on another one before I decided to coax him into talking to me.

"I'm Mercedes," I said, loosening an alternator bolt. "What do you want me to call you?"

His eyes lit for a minute. "Mercedes the Volkswagen mechanic?" His face closed down quickly, and he mumbled, "Sorry. Bet you've heard that a lot."

I grinned at him and handed him the bolt I'd taken out and started on the next. "Yep. But I work on Mercedes, too-anything German-made. Porsche, Audi, BMW, and even the odd Opel or two. Mostly old stuff, out of dealer warranty, though I have the computers for most of the newer ones when they come in."

I turned my head away from him so I could get a better look at the stubborn second bolt. "You can call me Mercedes or Mercy, whichever you like. What do you want me to call you?"

I don't like forcing people into a corner where they have to lie to you. If he was a runaway, he probably wouldn't give me a real name, but I needed something better to call him than «boy» or "hey, you" if I was going to work with him.

"Call me Mac," he said after a pause.

The pause was a dead giveaway that it wasn't the name he usually went by. It would do for now.

"Well then, Mac," I said. "Would you give the Jetta's owner a call and tell him his car is ready?" I nodded toward the first car we had finished. "There's an invoice on the printer. His number is on the invoice along with the final cost of the transmission swap. When I get this belt replaced I'll take you to lunch-part of the wages."

"Okay," he said, sounding a little lost. He started for the door to the showers but I stopped him. The laundry and shower were in the back of the shop, but the office was on the side of the garage, next to a parking lot customers used.

"The office is straight through the gray door," I told him. "There's a cloth next to the phone you can use to hold the receiver so it doesn't get covered with grease."