“No? Let me have the close-ups of the extractor marks and scratches,” Rhyme said. “And the ones of the lands and grooves on the slugs.”

Shean placed them on a table for Rhyme to examine. “But we don’t have known samples from Gabe’s Glock. I asked him and—”

“I know you don’t.”

“Oh, right, otherwise we would have identified the gun.”

“Exactly.” Rhyme’s brow furrowed as he examined the pictures. “Sachs?”

Dance recalled that though they were both romantic and professional partners, they tended to refer to each other by their last names. Which she found rather charming.

Sachs studied the pictures too. Apparently she knew exactly what he was interested in. “I’d say four thousand.”

“Good,” Rhyme announced. Then: “I need the serial number of Fuentes’s gun.”

A fast computer search revealed it. Rhyme glanced at the number. “Okay, the gun was made four years ago by our talented friends in Austria. Call this Fuentes and ask him when he got it and how often he fired it.”

Harutyun made this call. He jotted notes and looked up. “You need anything else from Gabriel, Lincoln?”

“No. Not now. Maybe later. Don’t let him wander too far from his mobile.”

The answer was that he’d bought the weapon new—three years ago—and took it to the range twice a month or so. He would typically fire fifty rounds.

Rhyme gazed into the air over the local officers. “Fifty rounds, every two weeks, for three years means it’s been fired about thirty-nine hundred times. From the pictures of the shells and the slugs, Sachs estimated they came from a gun that had been fired about four thousand times. Good eye.” He glanced at her.

Sachs explained to the others, “The distension of the brass, cracks around the neck and the spread of the lands and grooves are typical of a gun fired with that frequency.”

Shean was nodding as if memorizing this. “So it is Gabe’s weapon.”

“Most likely,” Sachs said.

Rhyme called, “Microscope! Charlie, I need a ’scope.”

“Well, the scanning electron—”

“No, no, no. Obviously that’s not what I need. We’re not at the molecular level. Optics, optics!”

“Oh, sure.”

The man had a tech wheel over two heavy compound microscopes—one a biological, which illuminated translucent samples from beneath, and a metallurgic model, which shone light down on opaque samples. Shean was setting it up when Rhyme shooed him away. Using his right hand he prepared several slides from the trace and examined them one by one, using both of the scopes.

“And good job with the analysis of the trace, Charlie. Let me see the original printouts.”

Shean called them up and Rhyme studied the screen and then some of the samples visually. Peering through the eyepieces, he was muttering to himself. Dance couldn’t hear everything he said but caught an occasional, “Good, good … What the hell is that? Oh, bullshit … Hm, interesting … Good.”

Rhyme set slides out and pointed. “Fungi database on that one and I need a fast reagent test on those.”