Pete(?) - anyway, the other one - said, "I was at a briefing about theft detectors a couple of weeks ago. From what I heard, they operate by spotting guilt in a perpetrator's soul. Trouble is, most perpetrators don't feel enough guilt to set 'em off."

Judy said, "I understand they've recently identified the sorcerous component of intent. That may make some new lands of anti-theft magic possible, provided the discrimination spell routines are sensitive enough to tell real larceny from a merchant's legitimate appetite for profit"

The guards had given her the usual looks a man gives an attractive woman. They were polite about it - nothing to bother her or me. Now they looked at her in a different way.

I'd seen that happen a lot of times before, when people realized how sharp she was. I just smiled; I've known it for years.

"I sure hope they make something like mat work," Pete said. "An awful lot of stuff you see here is stolen. Everybody knows it, but how do you prove it? If you could-"

"It'll happen," Judy said. "Not tomorrow, probably not the day after, either, but ifU happen. The principles are there.

The gremlins are in engineering the actuating sorcery and the support systems."

"By God, I'd cheer for anything that made my job easier for once," Pete said.

"I'd cheer louder if I thought the techniques would just be used for tracking down thieves, but I've got a bad feeling they won't," Judy said. The more effective magic becomes, the more the powers that be will use it to poke into ordinary people's lives. That's the way things seem to work, anyhow."

Pete and Luke represented the powers that be. Now they looked at each other, but neither of them said anything - I told you they were polite. For that matter, I'm part of the powers that be, too, but I stood with Judy on this one. People often don't realize how precious just being left alone is.

Even if the guards had decided to aigue, we'd have been too busy to cany it very far: dealers started showing up. Pete and Luke checked their permits and made sure they'd paid for their stall space. Judy and I monitored the spellchecker as they came through the gateway. Some of them had their goods and stall setups on carts that they pushed or pulled, others piled them onto little carpets. That sort isn't Byway - legal, but it's awfully handy for hauling things around.

Quite a few dealers weren't happy about passing in front of a spellchecker. "What is this, the airport?" one of them grumbled.

So many dealers asked questions that my spiel got real smooth real fast By the time the first four or five had gone by, I'd taken out my EPA sigil and set it on top of the spellchecker. I'd point to it and say, "We're looking for a very specific contaminant that we have reason to believe is being sold at swap meets, perhaps unwittingly. Nothing else we notice will get cited."

That probably wasn't quite true; if somebody'd come by with something as conspicuously illegal as a crate of black lotuses (better known as Kali's flowers), for instance, we wouldn't have let him take them in. But, to my relief, nothing like that happened, and the explanation kept the dealers from getting antsy.

Heavens, what a lot of stuff there was! Clothes, food, jewelry, nostrums (the microimps in the spellchecker seemed dubious a few times, but not dubious enough to make me stop anybody), ethemet receiver imp modules (I wondered how many of those were stolen), toys both mechanical and sorcerous, guitars, grimoires (Judy looked more than scornful at the quality)-I could go on for a lot longer.

The dealers were as varied as the stuff they sold: men, women, blonds, blacks, Aztedans, Persians, Hanese, Samoans, Indians in dhotis and saris, the other flavor Indians in feathers. I watched one bronze-skinned fellow slip out of his work shirt and put on a feather bonnet. He noticed me watching him, grinned land of sheepishly. "Gotta look authentic if you want the people to buy your medicine, man," he said as he pushed his cart past me.

"Why not?" I answered agreeably. I glanced down at the spellchecker. From what the microimps had to say about them, the medicines weren't strong enough to be worth buying. I wondered if the alleged Indian was even as genuine as the stuff he sold.

The next fellows through were a pair of Aztecans. The had a rug with their stuff on it, and were chatting with each other in Spainish.

Judy gave me a hard shot in the ribs with her elbow.

"Huh?" I said. Then I looked at the ground glass in the spellchecker. If they hadn't been trained to tell what they were sensing, the little imps would have run and hid. As it was - My stomach lurched when I saw what they reported.

"Hold on there, you two," I said sharply They hadn't noticed me or the spellchecker. "What's the matter?" one of them asked at the same time as the other one said, "Who are you?"

I picked up my sigil. "Environmental Perfection Agency,"

I said. "What do you have in those boxes?"

"Nostrums," one of them answered. "I got a friend, his brother-in-law hunts dragons down in Aztecia. He gets the blood, sells some to us, we dilute it, sell some here. Everybody makes some money."

He didn't sound like a crook, just a fellow doing a job.

That's what he looked like, too, he and his friend both: ordinary guys in work shoes and jeans, cotton tunics and caps.

The first thing you learn is, you can't tell by looking. Pete and Luke came alert They didn't move toward us, not yet, but they quivered like lycanthropes just before the full moon rises.

"Which one of you is Jose?" Judy asked suddenly.

The one in the red cap jerked in surprise. "How'd you know that, lady?"

I unreeled the long probe from the spellchecker (actually, I wished I had one of those eleven-foot Rumanians). Tm going to have to ask you to open one of those jars of dragon blood for me," I said.

Jose shrugged. "Sure. Why not?" He flipped the lid off one of the boxes. The jars inside looked like the ones Cuauhtemoc Hemandez kept in his workroom. Once upon a time, they'd held mayonnaise. Now… As soon as Jose unscrewed a top, I knew what they held: Judy, who was at the spellchecker, made a small, strangled noise. I'd told her what kind of stuff was in there, but hearing about it doesn't pack the same punch as seeing it in the ground glass.

I waved to Pete and Luke. They came trotting over. The fellow in the blue cap, who'd kept pretty quiet up till now, saw them and said, "What the hell's going on?"

Thafc just what I want to know," I snapped. Considering what was in the jars, I meant it literally. I turned back to Jose.

"You ever sell any of this, ah, 'dragon blood' to a cumndero named Cuauhtemoc Hemandez?"

"I sell to lots of people, man," he answered. They pay cash. I don't ask who they are. You know how that goes." He spread his hands and looked at me, one man of the world to another.

I knew how it went, all right. It meant he didn't pay taxes on the money he made at the swap meets. It's theoretically possible for the Crown to keep track of all the crowns in the Confederation. The financial wi2ards in the gray flannel suits back in D.StC. would love to do it, too. Trouble is, of course, that the sorcery involved is so complex that it makes getting the Garuda Bird off the ground look like tossing a roc by comparison. And so people like Jose will go on cheating on what they owe, and people like you and me will end up footing the bill for them.

Except now Jose was facing some time at public expense of an altogether different sort. I said, "By what the spellchecker shows me, sir, there isn't any dragon blood in here.

There's human blood, and human skin, and"-I looked back at Judy, who nodded-"a godawful strong stink of Huitzilopochdi."

Jose and blue-cap (I found out later his name was Carlos, so I'll call him that) looked at each other. If they weren't utterly appalled, they should have been making their money at the light-and-magic shows, not swap meets. They wouldn't have gotten it in cash, but they'd have made enough to keep from complaining.