The Bone Collector

before lumber companies started pressure-treating. Piers, docks, railroad ties.”
    “Maybe we’ve got a train buff here,” Sellitto said. “Remember the tracks this morning.”
    “Could be.” Rhyme ordered, “Check for cellular compression, Mel.”
    The tech examined the splinter under the compound microscope. “It’s compressed all right. But with thegrain. Not against it. Not a railroad tie. This is from a post or column. Weight-bearing.”
    A bone . . . an old wooden post . . .
    “I see dirt embedded in the wood. That tell us anything?”
    Cooper set a large pad of newsprint on the table, tore the cover off. He held the splinter over the pad and brushed some dirt from cracks in the wood. He examined the speckles lying on the white paper—a reverse constellation.
    “You have enough for a density-gradient test?” Rhyme asked.
    In a D-G test, dirt is poured into a tube containing liquids of different specific gravities. The soil separates and each particle hangs suspended according to its own gravity. Rhyme had established a very extensive library of density-gradient profiles for dirt from all over the five boroughs. Unfortunately the test only worked with a fair amount of soil; Cooper didn’t think they had enough. “We could try it but we’d have to use the entire sample. And if it didn’t work we wouldn’t have anything left for other tests.”
    Rhyme instructed him to do a visual then analyze it in the GC-MS—the chromatograph-spectrometer.
    The technician brushed some dirt onto a slide. He gazed at it for a few minutes under the compound microscope. “This is strange, Lincoln. It’s topsoil. With an unusually high level of vegetation in it. But it’s in a curious form. Very deteriorated, very decomposed.” He looked up and Rhyme noticed the dark lines under his eyes from the eyepieces. He remembered that after hours of lab work the marks were quite pronounced and that occasionally a forensic tech would emerge from the IRD lab only to be greeted by a chorus of Rocky Raccoon.
    “Burn it,” Rhyme ordered.
    Cooper mounted a sample in the GC-MS unit. The machine rumbled to life and there was a hiss. “A minute or two.”
    “While we’re waiting,” Rhyme said, “the bone . . . I keep wondering about the bone. ’Scope it, Mel.”
    Cooper carefully set the bone onto the examination stage of the compound microscope. He went over it carefully. “Whoa, got something here.”
    “What?”
    “Very small. Transparent. Hand me the hemostat,” Cooper said to Sachs, nodding at a pair of gripper tweezers. She handed them to him and he carefully probed in the marrow of the bone. He lifted something out.
    “A tiny piece of regenerated cellulose,” Cooper announced.
    “Cellophane,” Rhyme said. “Tell me more.”
    “Stretch and pinch marks. I’d say he didn’t leave it intentionally; there are no cut edges. It’s not inconsistent with heavy-duty cello,” Cooper said.
    “ ‘Not inconsistent.’ ” Rhyme scowled. “I don’t like his hedges.”
    “We have to hedge, Lincoln,” Cooper said cheerfully.
    “ ‘Associate with.’ ‘Suggest.’ I particularly hate ‘not inconsistent.’ ”
    “Very versatile,” Cooper said. “The boldest I’ll be is that it’s probably commercial butcher or grocery store cellophane. Not Saran Wrap. Definitely not generic-brand wrap.”
    Jerry Banks walked inside from the hallway. “Bad news. The Secure-Pro company doesn’t keep any records on combinations. A machine sets them at random.”
    “Ah.”
    “But interesting . . . they said they get calls from the police all the time about their products and you’re the first one who’s ever thought of tracing a lock through the combination.”
    “How ‘interesting’ can it be if it’s a dead end?” Rhyme grumbled and turned to Mel Cooper, who was shaking his head as he stared at the GC-MS computer. “What?”
    “Got that soil sample result. But I’m afraid the machine might be on the fritz. The nitrogen’s off the charts. We should run it again, use more sample this time.”
    Rhyme instructed him to go ahead. His eyes turned back to the bone. “Mel, how recent was the kill?”
    He examined some scrapings under the electron microscope.
    “Minimal bacteria clusters. Bambi here was recently deceased, looks like. Or just out of the fridge about eight hours.”
    “So our perp just bought it,” Rhyme said.
    “Or a month ago and froze it,” Sellitto suggested.
    “No,”