"But the killer doesn't know that."

Wesley looked speculatively at me.

"That's right."

"Not unless he's a scientist or something," Abby interjected.

"We'll assume he isn't," I told them. "I suspect he never gave DNA profiling a thought until he started reading about it in the papers. I doubt he understands the concept very well."

"I'll explain the procedure in my story," Abby thought out loud. "I'll make him understand it just enough to freak him."

"Just enough to make him think we know about his defect," Wesley agreed. "If he has a defect… That's what worries me, Kay."

He looked levelly at me. "What if he doesn't?"

I patiently went over it again. "What continues to stand out to me is Matt Petersen's reference to 'pancakes,' to the smell inside the bedroom reminding him of pancakes, of something sweet but sweaty."

"Maple syrup," Wesley recalled.

"Yes. If the killer has a body odor reminiscent of maple syrup, he may have some sort of anomaly, some type of metabolic disorder. Specifically, 'maple syrup urine disease.'"

"And it's genetic?" Wesley had asked this twice.

"That's the beauty of it, Benton. If he has it, it's in his DNA somewhere."

"I've never heard of it," Abby said. "This disease."

"Well, it's not exactly your common cold."

"Then exactly what is it?"

I got up from my desk and went to a bookcase. Sliding out the fat Textbook of Medicine, I opened it to the right page and set it before them.

"It's an enzyme defect," I explained as I sat back down. "The defect results in amino acids accumulating in the body like a poison. In the classic or acute form, the person suffers severe mental retardation and/or death at infancy, which is why it's rare to find healthy adults of sound mind who suffer from the disease. But it's possible. In its mild form, which would have to be what the killer suffers from if this is his affliction, postnatal development is normal, symptoms are intermittent, and the disease can be treated through a low-protein diet, and possibly through dietary supplements-specifically, thiamine, or vitamin B1, at ten times the normal daily intake."

"In other words," Wesley said, leaning forward and frowning as he scanned the book, "he could suffer from the mild form, lead a fairly normal life, be smart as hell-but stink?"

I nodded. "The most common indication of maple syrup urine disease is a characteristic odor, a distinctive maple syrupy odor of the urine and perspiration. The symptoms are going to be more acute when he's under stress, the odor more pronounced when he's doing what stresses him most, which is committing these murders. The odor's going to get into his clothing. He's going to have a long history of being self-conscious about his problem."

"You wouldn't smell it in his seminal fluid?" Wesley asked.

"Not necessarily."

"Well," Abby said, "if he's got this body odor, then he must take a lot of showers. If he works around people. They'd notice it, the smell."

I didn't respond.

She didn't know about the glittery residue, and I wasn't going to tell her. If the killer has this chronic odor, it wouldn't be the least bit unusual for him to be compulsive about washing his armpits, his face and hands, frequently throughout the day while he's exposed to people who might notice his problem. He might be washing himself while at work, where there might be a dispenser of borax soap in the men's room.

"It's a gamble." Wesley leaned back in his chair. "Jeez."

Shaking his head. "If the smell Petersen mentioned was something he imagined or something he confused with another odor maybe a cologne the killer was wearing-we're going to look like fools. The squirrel's going to be all the more certain we don't know what the hell we're doing."

"I don't think Petersen imagined the smell," I said with conviction. "As shocked as he was when he found his wife's body, the smell had to be unusual and potent for Petersen to notice and remember it. I can't think of a single cologne that would smell like sweaty maple syrup. I'm speculating the killer was sweating profusely, that he'd left the bedroom maybe minutes before Petersen walked in."

"The disease causes retardation…" Abby was flipping through the book.

"If it's not treated immediately after birth," I repeated.

"Well, this bastard isn't retarded." She looked up at me, her eyes hard.

"Of course he isn't," Wesley agreed. "Psychopaths are anything but stupid. What we want to do is make the guy think we think he's stupid. Hit him where it hurts-his goddam pride, which is hooked up with his grandiose notions of his off-the-charts IQ."

"This disease," I told them, "could do that. If he has it, he's going to know it. Possibly it runs in his family. He's going to be hyper-sensitive, not only about his body odor, but also about the mental deficiencies the defect is known to cause."

Abby was making notes to herself. Wesley was staring off at the wall, his face tense. He didn't look happy.

Blowing in frustration, he said, "I just don't know, Kay. If the guy doesn't have this maple syrup whatever…"

He shook his head. "He'll be on to us in a flash. It could set the investigation back."

"You can't set back something that is already backed into a corner," I said evenly. "I have no intention of naming the disease in the article."

I turned to Abby. "We'll refer to it as a metabolic disorder. This could be a number of things. He's going to worry. Maybe it's something he doesn't know he has. He thinks he's in perfect health? How can he be sure? He's never had a team of genetic engineers studying his body fluids before. Even if the guy's a physician, he can't rule out the possibility he has an abnormality that's been latent most of his life, sitting there like a bomb waiting to go off. We'll plant the anxiety in his head. Let him stew over it. Hell, let him think he's got something fatal.

Maybe it will send him to the nearest clinic for a physical. Maybe it will send him to the nearest medical library. The police can make a check, see who seeks out a local doctor or frantically begins riffling through medical reference books at one of the libraries. If he's the one who's been breaking into the computer here, he'll probably do it again. Whatever happens, my gut tells me something will happen. It's going to rattle his cage."

The three of us spent the next hour drafting the language in Abby's article.

"We can't have attribution," she insisted. "No way. If these quotes are attributed to the chief medical examiner, it will sound fishy because you've refused to talk in the past. And you've been ordered not to talk now. It's got to look like the information was leaked."

"Well," I commented dryly, "I suppose you can pull your famous 'medical source' out of your hat."

Abby read the draft aloud. It didn't set well with me. It was too vague. "Alleged" this and "possible" that.

If only we had his blood. The enzyme defect, if it existed, could be assayed in his leukocytes, his white blood cells. If only we had something.

As if on cue my telephone buzzed. It was Rose. "Dr. Scarpetta, Sergeant Marino's here. He says it's urgent."

I met him in the lobby. He was carrying a bag, the familiar gray plastic bag used to hold clothing connected to criminal cases.