FOR THE NEXT COUPLE OF WEEKS I HEARD NOTHING FROM GABBY. I was also not on Claudel’s dialing list. He’d cut me out of the loop. I learned about Isabelle Gagnon’s life through Pierre LaManche.

She’d lived with her brother and his lover in St. Édouard, a working-class neighborhood northeast of Centre-ville. She worked in a lover’s boutique, a small shop off St. Denis specializing in unisex clothes and paraphernalia. Une Tranche de Vie. A Slice of Life. The brother, who was a baker, had thought of the name. The irony of it was depressing.

Isabelle disappeared on Friday, April 1. According to the brother, she was a regular at some of the bars on St. Denis, and had been out late the night before. He thought he’d heard her come in around 2 A.M., but didn’t check. The two men left for work early the next morning. A neighbor saw her at 1 P.M. Isabelle was expected at the boutique at 4 P.M. She never showed up. Her remains were discovered nine weeks later at Le Grand Séminaire. She was twenty-three.

LaManche came into my office late one afternoon to see if I’d finished my analysis.

“There are multiple fractures of the skull,” I said. “It took quite a bit of reconstructing.”

“Oui.”

I took the skull from its cork ring.

“She was hit at least three times. This is the first.”

I pointed to a small, saucerlike crater. A series of concentric circles expanded outward from its epicenter, like rings on a shooting target.

“The first blow wasn’t hard enough to shatter her skull. It just caused a depression fracture of the outer table. Then he hit her here.”

I indicated the center of a starburst pattern of fracture lines. Looping through the stellate system was a series of curvilinear fractures. The rays and the circles interlaced to form a spiderweb of damage.

“This blow was much harder, and caused a massive comminuted fracture. Her skull shattered.”

It had taken long hours to reassemble the pieces. Traces of glue were visible along the fragment edges.

He listened, absorbed, his eyes driving back and forth from the skull to my face so intently they seemed to burrow a channel through the air.

“Then he hit her here.”

I traced a runner from another starburst system toward an arm of the one I’d just shown him. The second linear break came up to the first and stopped, like a country road at a T-intersection.

“This blow came later. New fractures will be arrested by preexisting ones. New lines won’t cross old ones, so this one had to have come last.”

“Oui.”

“The blows were probably delivered from the back and slightly to the right.”

“Oui.”

He did this to me often. The absence of feedback was no indication of a lack of interest. Or understanding. Pierre LaManche missed nothing. I doubt he ever needed second explanations. The monosyllabic response was his way of forcing you to organize your thoughts. A sort of dry-run jury presentation. I forged on.

“When a skull is hit it acts like a balloon. For a fraction of a second the bone pushes in at the point of impact, and bulges out on the opposite side. So the damage isn’t restricted to the place the head was struck.”

I looked to see if he was with me. He was.

“Because of the architecture of the skull, the forces caused by a sudden impact travel along certain pathways. The bone fails, or breaks, somewhat predictably.”

I pointed to the forehead.

“For example, an impact here can result in damage to the orbits or face.”

I indicated the back of the skull.

“A blow here often causes side-to-side fractures of the base of the skull.”

He nodded.

“In this case, there are two comminuted fractures and one depressed fracture of the posterior right parietal. There are several linear fractures that start on the opposite side of the skull and travel toward the damage in the right parietal. This suggests she was struck from the back and to her right.”

“Three times,” he said.

“Three times,” I confirmed.

“Did it kill her?” He knew what my answer would be.

“Could have. I can’t say.”

“Any other signs of cause?”

“No bullets, no stab marks, no other fractures. I’ve got some odd gashes on the vertebrae, but I’m not really sure what they mean.”

“Due to the dismemberment?”

I shook my head. “I don’t think so. They’re not in the right place.”

I replaced the skull in its ring.

“The dismemberment was very clean. He didn’t just chop the limbs off. He severed them neatly at the joints. Remember the Gagne case? Or Valencia?”

He thought a minute. In a rare display of movement he tipped his head to the right, then to the left, like a dog cuing in on the crinkle of cellophane.

“Gagne came in, oh, maybe two years ago,” I prompted. “He was wrapped in layers of blankets, trussed up with packaging tape. His legs had been sawed off and packaged individually.”

At the time it had reminded me of the ancient Egyptians. Before mummification they removed the internal organs and preserved them. The viscera were then bundled separately and placed with the body. Gagne’s killers had done the same with his legs.

“Ah, oui. I remember the case.”

“Gagne’s legs were sawed off below the knees. Same with Valencia. His arms and legs were cut several inches above or below the joints.”

Valencia had gotten greedy on a drug deal. He came to us in a hockey bag.

“In both those cases the limbs were hacked off at the most convenient place. In this case the guy neatly disconnected the joints. Look.”

I showed him a diagram. I’d used a standard autopsy drawing to indicate the points at which the body had been cut. One line ran through the throat. Others bisected the shoulder, hip, and knee joints.

“He cut the head off at the level of the sixth cervical vertebrae. He removed the arms at the shoulder joints, and the legs at the hip sockets. The lower legs were separated at the knee joints.”

I picked up the left scapula.

“See how the cuts surround the glenoid fossa?”

He studied the marks, sets of parallel grooves circling the joint surface.

“Same thing with the leg.” I switched the scapula for the pelvis. “Look at the acetabulum. He went right into the socket.”

LaManche inspected the deep cup that accommodates the head of the femur. Numerous gashes scarred its walls. Silently, I took the pelvis and handed him the femur. Its neck was ringed by pairs of parallel cuts.

He looked at the bone a long time, then returned it to the table.

“The only place he deviated was with the hands. There he just sliced right through the bone.”

I showed him a radius.

“Odd.”

“Yes.”

“Which is more typical? This or the others?”

“The others. Usually you want to cut a body up so it’s easier to dispose of, so you do it the fastest way possible. Grab a saw and hack away. This guy took more time.”

“Hmm. What does it mean?”

I’d given the question quite a bit of thought.

“I don’t know.”

Neither of us spoke for a few moments.

“The family wants the body for burial. I’m going to hold off as long as I can, but be sure you’ve got good pictures and everything you will need if we go to trial on this one.”

“I plan to take sections from two or three of the cut marks. I’ll look at them under the microscope to see if I can pinpoint the tool type.”

I chose my next words carefully, and watched him closely for a reaction.

“If I get any good features I’d like to try comparing these cuts to some I have on another case.”

The corners of his mouth twitched almost imperceptibly. I couldn’t tell if it was amusement or annoyance. Or perhaps I’d imagined it.

After a pause he said, “Yes. Monsieur Claudel has mentioned this.” He looked directly at me. “Tell me why you think these cases are connected.”

I outlined the similarities I saw between the Trottier and Gagnon cases. Bludgeoning. Cutting of the body after death. The use of the plastic bags. Dumping in a secluded area.

“Are these both CUM cases?”

“Gagnon is. Trottier is SQ. She was found in the St. Jerome.”

As in many cities, questions of jurisdiction can be tricky in Montreal. The city lies on an island in the middle of the St. Lawrence. The Communauté Urbaine de Montréal police handle murders occurring on the island itself. Off the island, they fall to local police departments, or to La Sûreté du Québec. Coordination is not always good.

After a pause he said, “Monsieur Claudel can be”—he hesitated—“difficult. Follow through on your comparison. Let me know if you need anything.”

Later that week I’d photographed the cut marks with a photomicroscope, using varying angles, magnifications, and intensities of light. I hoped to bring out details of their internal structure. I’d also removed small segments of bone from several joint surfaces. I planned to view them with the scanning electron microscope. Instead I was up to my neck in bones for the next two weeks.

A partially clothed skeleton was discovered by kids hiking in a provincial park. A badly decomposed body washed up on the shore of Lac St. Louis. While cleaning the basement of their newly purchased home, a couple found a trunk full of human skulls covered with wax, blood and feathers. Each find came to me.

The remains from Lac St. Louis were presumed to be those of a gentleman who died in a boating mishap the previous fall when a competitor took exception to his freelancing as a cigarette smuggler. I was putting his skull back together when the call came.

I’d been expecting it, though not this soon. As I listened my heart raced and the blood below my breastbone felt fizzy, like carbonated soda shaken in a bottle. I felt hot all over.

“She’s been dead less than six hours,” LaManche was saying. “I think you’d better take a look.”