Cooper examined the results. “You’re right, Lincoln. It’s RDX. Also oil. And this is weird—starch . . . ”

“Starch!” Rhyme cried. “That’s what I smelled. It’s guar flour . . . ”

Cooper laughed as those very words popped up on the computer screen. “How’d you know?”

“Because it’s military dynamite.”

“But there’s no nitroglycerine,” Cooper protested. The active ingredient in dynamite.

“No, no, it’s not real dynamite,” Rhyme said. “It’s a mixture of RDX, TNT, motor oil, and the guar flour. You don’t see it very often.”

“Military, huh?” Sellitto said. “Points to Hansen.”

“That it does.”

The tech mounted samples on his compound ’scope’s stage.

The images appeared simultaneously on Rhyme’s computer screen. Bits of fiber, wires, scraps, splinters, dust.

He was reminded of a similar image from years ago, though in circumstances very different. Looking through a heavy brass kaleidoscope he’d bought as a birthday present for a friend. Claire Trilling, beautiful and stylish. Rhyme had found the kaleidoscope in a store in SoHo. The two of them had spent an evening sharing a bottle of merlot and trying to guess what kind of exotic crystals or gemstones were making the astonishing images in the eyepiece. Finally, Claire, nearly as scientifically curious as Rhyme, had unscrewed the bottom of the tube and emptied the contents onto a table. They’d laughed. The objects were nothing more than scraps of metal, wood shavings, a broken paper clip, torn shreds from the Yellow Pages, thumbtacks.

Rhyme pushed those memories aside and concentrated on the objects he was seeing on the screen: A fragment of waxed manila paper—what the military dynamite had been wrapped in. Fibers—rayon and cotton—from the detonating cord the Dancer had tied around the dynamite, which would crumble too easily to mold around the cord. A fragment of aluminum and a tiny colored wire—from the electric blasting cap. More wire and an eraser-size piece of carbon from the battery.

“The timer,” Rhyme called. “I want to see the timer.”

Cooper lifted a small plastic bag from the table.

Inside was the still, cold heart of the bomb.

It was in nearly perfect shape, surprising Rhyme. Ah, your first slipup, he thought, speaking silently to the Dancer. Most bombers will pack explosives around the detonating system to destroy clues. But here the Dancer had accidentally placed the timer behind a thick steel lip in the metal housing that held the bomb. The lip had protected the timer from the blast.

Rhyme’s neck stung as he strained forward, looking at the bent clock face.

Cooper scrutinized the device. “I’ve got the model number and manufacturer.”

“Run everything through ERC.”

The FBI’s Explosives Reference Collection was the most extensive database on explosive devices in the world. It included information on all bombs reported in the United States as well as actual physical evidence from many of them. Certain items in the collection were antiques, dating back to the 1920s.

Cooper typed on his computer keyboard. Five seconds later his modem whistled and crackled.