“Sounds like a good idea,” I said. “You know any good cadaver dogs?”
“Actually, yes,” said Arpad. “A German shepherd named Cherokee. He found some bare human bones in a creek bed up near Bristol, which isn’t particularly amazing; he found a freshly drowned man in twenty feet of water in the Big South Fork River, which is rather amazing. I actually worked with Cherokee to help calibrate the sniffer. I ran different decomp samples past him to see if he’d alert on them — to make sure he’d recognize them as human remains. Then I repeated the process with synthetic, laboratory mixtures of a few of the key chemicals in decomp. Cherokee alerted on them; so did the sniffer. All that was indoors. Then we went out into the woods, where we did all that again with buried samples. The dog found them all; so did the sniffer.”
Thornton settled back in his chair and drummed his fingers together. “So, no offense intended,” he said, “but what’s the sniffer got that the dog doesn’t have?”
“It’s got stamina,” said Arpad. “A dog’s nose gives out pretty quickly — the neurons that send signals to the brain just get tired and quit sending. A cadaver dog can work intensely for maybe half an hour, tops, then he’s got to rest. The only thing that gives out in the sniffer is the battery, and that takes sixty seconds to replace.”
Thornton nodded, satisfied. “You reckon we could get Cherokee out here anytime soon to scout around, help us narrow down the search area?”
“I’ll call and see,” he said. “Where’s the search area?” He reached back to a credenza tucked beneath the window and grabbed a cylinder of rolled paper. Unfurling a topographic map of the Oak Ridge Reservation, he spread it on his desk and weighted the corners with books.
Thornton and I looked at each other. “There’s the rub,” I said. “We’re not exactly sure.” Arpad’s gaze swiveled from me to Thornton and back again. I laid one of the hillside pictures on the map. “We think it’s buried here, where this picture of this barn was taken.”
“And where’s the barn?”
“That’s the thing,” I said. “We don’t know where it is. Or was.”
He looked stunned. “You’re saying it could be — or could have been — anywhere on the reservation?” I nodded glumly. “And you don’t even know if it still exists?” I nodded again. “This is a chemical probe, guys, not a magic wand,” he said. “You’re talking about a search area that’s, what, fifty thousand acres? It would take a lifetime to probe this whole place. Several lifetimes. I don’t mind looking for a needle in a haystack, but this is fifty thousand haystacks. Call me when you can narrow it down to just one.”
As we drove away from the research complex, I said to Thornton, “Arpad’s a little low-key, but he’s really excited about this.”
Thornton guffawed. “Yeah,” he said. “And Miranda’s voting Republican in the next election.”
Now it was my turn to laugh. “Okay, he’s not so excited,” I admitted. “I was trying to be upbeat. Sorry we wasted the trip.”
“Wasn’t wasted,” he said. “I can call up Arpad’s sponsor at DOJ and tell him the gadget works. Long as you already know where the body is.” I must have looked alarmed, because he quickly added, “Kidding. I’m kidding.”
We headed east, back toward Oak Ridge and Knoxville, for about a mile, then Thornton pointed to a sign on the left. “There it is — SPALLATION NEUTRON SOURCE,” he said. “That’s my stop.” The road wound uphill in a series of gentle S-curves; at the top of the ridge sprawled an immense new building, five curving stories of green glass and brushed aluminum.
“Wow,” I said. “Arpad needs to make friends with these guys. They’ve got better digs.” I parked near the entrance in a spot marked VISITOR, though we could have taken our pick of dozens of other convenient spots. “More parking, too.”
“I think they’re still putting the finishing touches on this,” he said. “I don’t believe the neutrons are spallating fully just yet.”
“Remind me what spallation means,” I said, as we walked toward the glass doors.
“Comes from the same root word as spa-lat,” he said, then he laughed. “Nah, kidding again. It’s from spalling—chipping — like concrete does. Spallation’s a subatomic version of concrete chipping. This thing fires zillions of neutrons out a huge linear accelerator — see that long, straight dike of dirt there, running from the main building over to that smaller building way over there? I think the accelerator’s under there. Anyhow, it shoots neutrons at experimental targets or materials, and then people who are a lot smarter than I am figure out all sorts of important things about those materials, based on what happens when the neutrons bash into them.”
“Bash?”
“Bash. Splat. Wham. Take your pick. They’re all scientifically rigorous and precise.”
“Rigorous,” I said.
“And precise.”
“So they make radioisotopes here with some of the bashing?”
“Huh? I don’t think so,” he said. “Where’d you hear that?”
“Well, you have a meeting with an isotopes-production guy,” I said, “and we’re here.”
“Ah,” he said. “A reasonable inference, but wrong. They make the isotopes at a research reactor, the High-Flux Isotope Reactor. But the security’s tighter there, and the digs are better here. And the isotopes guy is apparently better connected than Arpad.”
Thornton’s “isotopes guy”—the program’s director, it turned out, named Barry Vandergriff — met us in the atrium and motioned us toward a cluster of overstuffed armchairs in an alcove of the lobby. I excused myself from their meeting and wandered among a series of displays that showed cutaway drawings of the facility’s accelerator and neutron-beam guides and experimental capabilities. Some of it was over my head, but I did grasp the notion that neutrons — and how they got deflected or scattered as they bounced off materials, or passed through them — could shed a lot of light on the molecular structure of metals, plastics, even the proteins that make up living organisms.
I had just begun to study a large, mercury-filled metal tank — the mercury served as an immense catcher’s mitt, apparently, to stop the neutron beam after it had passed through its experimental target — when Thornton tapped me on the shoulder. “I’m done,” he said. “You ready, or did you want to study up some more?”
“I’m ready,” I said. “I’m up to my eyeballs in neutrons.”
As we walked out of the building, Thornton said, “I wanted to talk to this guy to get more background on the iridium sources for radiographic cameras — who makes those sources, and how, and where.”
“And could he? Did he?”
“He could,” he said. “He did.”
“And?”
“For years, the only U.S. source of iridium-192 was the High-Flux Isotope Reactor, right here in Oak Ridge.”
“But now there are other U.S. sources?”
“No. Now not even HFIR’s making it. Too expensive. Now it’s imported from reactors in Belgium and the Netherlands and South Africa.”
“It’s cheaper to make it overseas and ship it in?”
“I guess so,” he said. “Maybe those governments subsidize the isotope reactors better, or maybe safety standards are lower or labor’s cheaper. Anyhow, that complicates our efforts to pin down where this came from.”
“Damn,” I said. “If this stuff has a half-life of only seventy-four days, how’s there time to ship it halfway around the world?”