“No,” he said. “We’ll go to my office.”

He led the way. I watched him walk. He was a small dark man with short legs, brisk, competent, a little older than me. He seemed nice enough. And I guessed he wasn’t stupid. Very few medics are. They have all kinds of complicated stuff to learn, before they get to be where they want to be. And I guessed he wasn’t unethical. Very few medics were that either, in my experience. They’re scientists at heart, and scientists generally retain a good-faith interest in facts and the truth. Or at least they retain some kind of innate curiosity. All of which was good, because this guy’s attitude was going to be crucial. He could stay out of our way, or he could sell us out with a single phone call.

His office was a plain square room full of original-issue gray steel desks and file cabinets. It was crowded. There were framed diplomas on the walls. There were shelves full of books and manuals. No specimen jars. No weird stuff pickled in formaldehyde. It could have been an army lawyer’s office, except the diplomas were from medical schools, not law schools.

He sat down in his rolling chair. Placed his file on his desk. Summer closed his door and leant on it. I stood in the middle of the floor, with the crowbar hanging in space. We all looked at each other. Waited to see who would make the opening bid.

“Carbone was a training accident,” the doctor said, like he was moving his first pawn two squares forward.

I nodded.

“No question,” I said, like I was moving my own pawn.

“I’m glad we’ve got that straight,” he said.

But he said it in a voice that meant: Can you believe this shit?

I heard Summer breathe out, because we had an ally. But we had an ally who wanted distance. We had an ally who wanted to hide behind an elaborate charade. And I didn’t altogether blame him. He owed years of service in exchange for his medical school tuition. Therefore he was cautious. Therefore he was an ally whose wishes we had to respect.

“Carbone fell and hit his head,” I said. “It’s a closed case. Pure accident, very unfortunate for all concerned.”

“But?”

I held the crowbar a little higher.

“I think this is what he hit his head on,” I said.

“Three times?”

“Maybe he bounced. Maybe there were dead twigs under the leaves, made the ground a little springy, like a trampoline.”

The doctor nodded. “Terrain can be like that, this time of year.”

“Lethal,” I said.

I lowered the crowbar again. Waited.

“Why did you bring it here?” the doctor asked.

“There might be an issue of contributory negligence,” I said. “Whoever left it lying around for Carbone to fall on might need a reprimand.”

The doctor nodded again. “Littering is a grave offense.”

“In this man’s army,” I said.

“What do you want me to do?”

“Nothing,” I said. “We’re here to help you out, is all. With it being a closed case, we figured you wouldn’t want to clutter your place up with those plaster casts you made. Of the wound site. We figured we could haul them to the trash for you.”

The doctor nodded for a third time.

“You could do that,” he said. “It would save me a trip.”

He paused for a long moment. Then he cleared the file away from in front of him and opened some drawers and laid sheets of clean white paper on the desktop and arranged half-a-dozen glass microscope slides on the paper.

“That thing looks heavy,” he said to me.

“It is,” I said.

“Maybe you should put it down. Take the weight off your shoulder.”

“Is that medical advice?”

“You don’t want ligament damage.”

“Where should I put it down?”

“Any flat surface you can find.”

I stepped forward and laid the crowbar gently on his desk, on top of the paper and the glass slides. Unhooked my boot lace and picked the knot out of it. Squatted down and threaded it back through all the eyelets. Tightened it up and tied it off. I looked up in time to see the doctor move a microscope slide. He picked it up and scraped it against the end of the crowbar where it was matted with blood and hair.

“Damn,” he said. “I got this slide all dirty. Very careless of me.”

He made the exact same error with five more slides.

“Are we interested in fingerprints?” he said.

I shook my head. “We’re assuming gloves.”

“We should check, I think. Contributory negligence is a serious matter.”

He opened another drawer and peeled a latex glove out of a box and snapped it on his hand. It made a tiny cloud of talcum dust. Then he picked the crowbar up and carried it out of the room.

He came back less than ten minutes later. He still had his glove on. The crowbar was washed clean. The black paint gleamed. It looked indistinguishable from new.

“No prints,” he said.

He put the crowbar down on his chair and pulled a file drawer and came out with a plain brown cardboard box. Opened it up and took out two chalk-white plaster casts. Both were about six inches long and both had Carbone handwritten in black ink on the underside. One was a positive, formed by pressing wet plaster into the wound. The other was a negative, formed by molding more plaster over the positive. The negative showed the shape of the wound the weapon had made, and therefore the positive showed the shape of the weapon itself.

The doctor put the positive on the chair next to the crowbar. Lined them up, parallel. The cast was about six inches long. It was white and a little pitted from the molding process but was otherwise identical to the smooth black iron. Absolutely identical. Same section, same thickness, same contours.

Then the doctor put the negative on the desk. It was a little bigger than the positive, and a little messier. It was an exact replica of the back of Carbone’s shattered skull. The doctor picked up the crowbar. Hefted it in his hand. Lined it up, speculatively. Brought it down, very slowly, one, for the first blow, then two for the second. Then three for the last. He touched it to the plaster. The third and final wound was the best defined. It was a clear three-quarter-inch trench in the plaster, and the crowbar fitted it perfectly.

“I’ll check the blood and the hair,” the doctor said. “Not that we don’t already know what the results will be.”

He lifted the crowbar out of the plaster and tried it again. It went in again, precisely, and deep. He lifted it out and balanced it across his open palms, like he was weighing it. Then he grasped it by the straighter end and swung it, like a batter going after a high fastball. He swung it again, harder, a compact, violent stroke. It looked big in his hands. Big, and a little heavy for him. A little out of control.

“Very strong man,” he said. “Vicious swing. Big tall guy, right-handed, physically very fit. But that describes a lot of people on this post, I guess.”

“There was no guy,” I said. “Carbone fell and hit his head.”

The doctor smiled briefly and balanced the bar across his palms again.

“It’s handsome, in its way,” he said. “Does that sound strange?”

I knew what he meant. It was a nice piece of steel, and it was everything it needed to be and nothing it didn’t. Like a Colt Detective Special, or a K-bar, or a cockroach. He slid it inside a long steel drawer. The metals scraped one on the other and then boomed faintly when he let it go and dropped it the final inch.

“I’ll keep it here,” he said. “If you like. Safer that way.”

“OK,” I said.

He closed the drawer.

“Are you right-handed?” he asked me.

“Yes,” I said. “I am.”

“Colonel Willard told me you did it,” he said. “But I didn’t believe him.”

“Why not?”

“You were very surprised when you saw who it was. When I put his face back on. You had a definite physical reaction. People can’t fake that sort of thing.”