Pause.

"What were they?"

"We're not sure yet. They're asking some guy over at U of M."

I looked at the word I'd written, swallowed hard.

"Any prints inside the glove we found with Gabby?" It was difficult to say her name.

"No."

"We knew there wouldn't be."

"Yeah."

I heard squad room noises in the background.

"I want to drop off a copy of this license photo so you'll have some idea what he looks like in case you meet him up close and personal. I still think it's better if you stick near home until we pop this a.s.shole."

"I'm coming in. If ident is done with the gloves I want to take them over to biology. Then Lacroix."

"I think you sh-"

"Cut the macho c.r.a.p, Ryan."

A breath drawn deeply, expelled.

"Are you holding out on me?"

"Brennan, what we know, you know."

"I'll be there in thirty minutes."

In less than half an hour I arrived at the lab. Ident had finished and sent the gloves to the biology section.

I looked at my watch-twelve-forty. I called the ident section at c.u.m headquarters to ask if I could see the photos taken at the St. Jacques apartment on Rue Berger. Lunchtime. The desk clerk would leave a message.

At one o'clock I walked over to the biology section. A woman with flyaway hair and a plump, Christmas angel face was shaking a gla.s.s vial. Two latex gloves lay on the counter behind her.

"Bonjour, Francoise."

"Ah. I thought I might see you today." The cherub eyes took on a worried expression. "I'm sorry. I don't quite know what to say to you."

"Merci. It's okay." I nodded at the gloves. "What have you got?"

"This one is clean. No blood." She gestured at Gabby's glove. "I'm just starting on the one from the kitchen. Would you like to watch?"

"Thank you."

"I've taken sc.r.a.pings from these brown spots and rehydrated the sample in saline."

She examined the liquid and placed the vial in a test tube tray. Then she withdrew a gla.s.s pipette with a long, hollow projection, held it over a flame to seal it, and twisted off the tip.

"I'll test for human blood first."

Removing a tiny bottle from the refrigerator, she broke the seal and inserted the thin, tubular point of a fresh pipette. Like a mosquito sucking blood, the antiserum moved up the tiny pipeline. She sealed the other end with her thumb.

She then inserted the long beak of the pipette into the fire-sealed pipette, released her thumb, and allowed the antiserum to dribble out. She spoke as she worked.

"The blood knows its own proteins, or antigens. If it recognizes foreigners, antigens that don't belong, it tries to destroy them with antibodies. Some antibodies blow up foreign antigens, others clump them together. That clumping is called an agglutination reaction.

"Antiserum is created in an animal, usually a rabbit or a chicken, by injecting it with the blood of another species. The animal's blood recognizes the invaders and produces antibodies to protect itself. Injecting an animal with human blood produces human antiserum. Injecting it with goat blood produces goat antiserum. Horse blood produces horse antiserum.

"Human antiserum creates an agglutination reaction when mixed with human blood. Watch. If this is human blood a visible precipitate will form in the test tube, right where the sample solution and the antiserum meet. We'll compare to the saline as a control."

She tossed the pipette into a biological waste container and picked up the vial with the Tanguay sample solution. Using another pipette, she sucked the sample up the tube, released it into the antiserum, and set the pipette into a holder.

"How long will it take?" I asked.

"That depends on the strength of the antiserum. Anywhere from three to fifteen minutes. This is pretty good. Shouldn't be more than five or six minutes."

We checked it after five, Francoise holding the pipettes under the Luxolamp, a black card behind for background. We checked again after ten. Fifteen. Nothing. No white band appeared between the antiserum and the sample solution. The mixture stayed as clear as the control saline.

"So. It's not human. Let's see if it's animal."

She went back to the refrigerator and withdrew a tray of small bottles.

"Can you tell the exact species?" I asked.

"No. Usually just family. Bovid. Cervid. Canid."

I looked at the tray. Written next to each bottle was an animal name. Goat. Rat. Horse. I pictured the paws in Tanguay's kitchen.

"Let's try dogs."

Nothing.

"What about something like a squirrel or a gopher?"

She thought a minute then reached for a bottle. "Maybe rat."

In less than four minutes a tiny parfait had formed in the tube, yellow above, clear below, a layer of foggy white between.

"Voila," said Francoise. "It's animal blood. Something small, a mammal, like a rodent or a ground hog or something. That's about all I'll be able to determine. I don't know if that helps you."

"Yes," I said. "That helps. May I use your phone?"

"Bien sur."

I dialed an extension down the hall.

"Lacroix."

I identified myself and explained what I wanted.

"Sure. Give me twenty minutes, I'm just finishing up a run."

I signed for the gloves, returned to my office, and spent the next half hour proofing and signing reports. Then I walked back to the corridor occupied by biology, and entered a door marked Incendie et Explosifs. Fire and Explosives.

A man in a lab coat stood in front of an enormous piece of machinery. A label identified it as an X-ray diffractometer. He didn't speak and I didn't say anything until he had removed a slide with a small white smear and placed it on a tray. Then he gave me eyes as soft as a Disney fawn, lids drooping, lashes curling back like petals on a daisy.

"Bonjour, Monsieur Lacroix. Comment ca va? Comment ca va?"

"Bien. Bien. You have them?"

I held up two plastic bags.

"Let's get started."

He led me into a small room with an apparatus the size of a photocopier, two monitors, and a printer. A periodic chart of the elements hung on the wall above.

Lacroix laid the evidence bags on a counter and pulled on surgical gloves. Gingerly, he withdrew each suspect glove, inspected it, then laid it on its plastic bag. The gloves stretched across his hands looked identical to those on the counter.

"First we look for gross characteristics, details of manufacturing. Weight. Density. Color. How the rims are finished." He turned each glove over and over, examining as he spoke. "These two look quite similar. Same rim technique. See?"

I looked. The wrist of each glove ended in a border that rolled outward onto itself.

"They're not all like that?"

"No. Some roll in, some roll out. These are both outies. So. Now we see what's in them."

He carried Gabby's glove to the machine, raised the cover, and placed it on a tray inside.

"With very small samples I use those little holders." He pointed to a tray of small plastic tubes. "I stretch a square of polypropylene window film across the holder, then use press-on tabs to make a sticky spot to hold the fragment. That's not necessary with this. We'll just put the whole glove in."

Lacroix flipped a switch and the apparatus whirred to life. A box positioned on a pole in one corner lit up, the word X RAY white against a red background. A panel of b.u.t.tons glowed, indicating the machine's condition. Red: X rays. White: Power. Orange: Shutter open.

For a few moments Lacroix adjusted dials, then he closed the cover and moved to a chair in front of the monitors.

"S'il vous plait." He indicated the other chair.

A desert landscape appeared on the first monitor, a granular backdrop of synclines and anticlines, with shadows and boulders scattered here and there. Superimposed on that scene was a series of concentric circles, the two smallest and most central shaped like footb.a.l.l.s. Two hashed lines intersected at right angles, forming a cross directly over the bull's-eye circles.

Lacroix adjusted the image by manipulating a joy stick. Boulders shifted in and out of the circles.

"That's the glove we're looking at, magnified eighty times. I'm just picking a target location. Each run samples an area of about three hundred microns, approximately the area inside the dotted circle. So you want to direct your X rays onto the best part of your sample."

He shifted the crosshairs a few more moments, then settled on a boulderless patch.

"There. That should be good."

He flipped a switch and the machine hummed.

"Now we're creating a vacuum. That'll take a couple of minutes. Then the scan. That's very quick."

"And this will determine what's in the glove."

"Oui. It's a form of X-ray a.n.a.lysis. X-ray microfluorescence can determine what elements are present in a sample."

The humming stopped and a pattern began to form on the right-hand monitor. A series of tiny red mounds sprouted across the bottom of the screen, then grew against a bright blue background, a thin yellow stripe up the middle of each. In the lower left-hand corner was an image of a keyboard, each key marked with the abbreviation for an element.

Lacroix typed in commands, and letters appeared on the screen. Some mounds remained small, others grew into tall peaks, like the giant termite castles I'd seen in Australia.

"C'est ca." That's it. Lacroix pointed at a column on the far right. It rose from the bottom to the top of the screen, where its top was truncated. A smaller peak to its right climbed to a quarter of its height. Both were marked Zn.

"Zinc. That's standard. It's found in all these gloves."

He indicated a pair of peaks to the far left, one low, the other rising three quarters of the distance up the screen. "That low one is magnesium. Mg. The tall one marked Si is silicon." Farther to the right a double peak bore the letter S.

"Sulfur."

A Ca peak spired halfway up the screen.

"Quite a bit of calcium."

Beyond the calcium a gap, then a series of low mounds, foothills to the zinc pinnacle. Fe.

"A little iron."

He leaned back and summarized. "Pretty common c.o.c.ktail. Lots of zinc, with silicon and calcium, the other major components. I'll print these, then let's test another spot."

We ran ten tests. All showed the same combination of elements.

"Right, then. The other glove."

We repeated the procedure with the glove from Tanguay's kitchen.

The peaks for zinc and sulfur were similar, but this glove contained more calcium, and had no iron, silicon, or magnesium. A small spike indicated the presence of pota.s.sium. It was the same on every run.

"What does this mean?" I asked, already certain of the answer.

"Each manufacturer uses a slightly different recipe for the latex. There will even be variation among gloves from the same company, but it will be within limits.

"So these gloves are not a pair?"