“Nothing’s ever completely destroyed, Sachs. Remember that.” Though as he wheeled closer and examined the bags, he admitted, “This was a bad one. See those fragments? That pile of aluminum on the left? The metal’s shattered, not bent. That means the device had a high brisance -”

“High…?” Sellitto asked.

“Brisance.” Rhyme explained: “Detonation rate. But even so, sixty to ninety percent of a bomb survives the blast. Well, not the explosive, of course. Though there’s always enough residue to type it. Oh, we’ve got plenty to work with here.”

“Plenty?” Dellray snorted a laugh. “Bad as puttin’ Humpty-Dumpty together again.”

“Ah, but that’s not our job, Fred,” Rhyme said briskly. “All we need to do is catch the son of a bitch who pushed him off the wall.” He wheeled farther down the table. “What’s it look like, Mel? I see battery, I see wire, I see timer. What else? Maybe bits of the container or packing?”

Suitcases have convicted more bombers than timers and detonators. It’s not talked about but unclaimed baggage is often donated to the FBI by airlines and blown up in an attempt to duplicate explosions and provide standards for criminalists. In the Pan Am flight 103 bombing, the FBI identified the bombers not through the explosive itself but through the Toshiba radio it had been hidden in, the Samsonite suitcase containing the radio, and the clothes packed around it. The clothing in the suitcase was traced back to a store in Sliema, Malta, whose owner identified a Libyan intelligence agent as the person who’d bought the garments.

But Cooper shook his head. “Nothing near the seat of detonation except bomb components.”

“So it wasn’t in a suitcase or flight bag,” Rhyme mused. “Interesting. How the hell did he get it on board? Where’d he plant it? Lon, read me the report from Chicago.”

“ ‘Difficult to determine exact blast location,’ ” Sellitto read, “ ‘because of extensive fire and destruction of aircraft. Site of device seems to be underneath and behind the cockpit.’ ”

“Underneath and behind. I wonder if a cargo bay’s there. Maybe…” Rhyme fell silent. His head swiveled back and forth, gazing at the evidence bags. “Wait, wait!” he shouted. “Mel, let me see those bits of metal there. Third bag from the left. The aluminum. Put it under a ’scope.”

Cooper had connected the video output of his compound microscope to Rhyme’s computer. What Cooper saw, Rhyme could see. The tech began mounting samples of the minuscule bits of debris on slides and running them under the ’scope.

A moment later Rhyme ordered, “Cursor down. Double click.”

The image on his computer screen magnified.

“There, look! The skin of the plane was blown inward.”

“Inward?” Sachs asked. “You mean the bomb was on the outside?”

“I think so, yes. What about it, Mel?”

“You’re right. Those polished rivet heads are all bent inward. It was outside, definitely.”

“A rocket maybe?” Dellray asked. “SAM?”

Reading from the report Sellitto said, “No radar blips consistent with missiles.”

Rhyme shook his head. “No, everything points to a bomb.”

“But on the outside?” Sellitto asked. “Never heard of that before.”

“That explains this,” Cooper called. The tech, wearing magnifying goggles and armed with a ceramic probe, was looking over bits of metal as fast as a cowboy counts heads in a herd. “Fragments of ferrous metal. Magnets. Wouldn’t stick to the aluminum skin but there was steel under it. And I’ve got bits of epoxy resin. He stuck the bomb on the outside with the magnets to hold it until the glue hardened.”

“And look at the shock waves in the epoxy,” Rhyme pointed out. “The glue wasn’t completely set, so he planted it not long before takeoff.”

“Can we brand the epoxy?”

“Nope. Generic composition. Sold everywhere.”

“Any hope of prints? Tell me true, Mel.”

Cooper’s answer was a faint, skeptical laugh. But he went through the motions anyway and scanned the fragments with the PoliLight wand. Nothing was evident except the blast residue. “Not a thing.”

“I want to smell it,” Rhyme announced.

“Smell it?” Sachs asked.

“With the brisance, we know it’s high explosive. I want to know exactly what kind.”

Many bombers used low explosives – substances that burn quickly but don’t explode unless confined in, say, a pipe or box. Gunpowder was the most common of these. High explosives – like plastic or TNT – detonate in their natural state and don’t need to be packed inside anything. They were expensive and hard to come by. The type and source of explosive could tell a lot about the bomber’s identity.

Sachs brought a bag to Rhyme’s chair and opened it. He inhaled.

“RDX,” Rhyme said, recognizing it immediately.

“Consistent with the brisance,” Cooper said. “You thinking C three or C four?” Cooper asked. RDX was the main component of these two plastic explosives, which were military; they were illegal for a civilian to possess.

“Not C three,” Rhyme said, again smelling the explosive as if it were a vintage Bordeaux. “No sweet smell… Not sure. And strange… I smell something else… GC it, Mel.”

The tech ran the sample through the gas chromatograph/mass spectrometer. This machine isolated elements in compounds and identified them. It could analyze samples as small as a millionth of a gram and, once it had determined what they were, could run the information through a database to determine, in many cases, brand names.

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.