“It stands to reason that this is the cargo the man in Cuba was talking about with his friend in Pyongyang,” said Sanchez. “The big kid.”

“What you’re saying is that somewhere there’s a smaller one still floating around,” said Thorpe.

“Worse than that,” said Winget. “Look at the rest of the telephone transcript.”

Thorpe turned back to the file and read to the end of the transcript. “The North Koreans have a replacement for the one on the plane.”

“It looks like it,” said Winget. “We’re talking a very serious problem here. Grounding that plane may have slowed them down but it didn’t stop them.”

“It appears the North Koreans are selling this stuff to private contractors,” said Sanchez. “There’s a lesson to be learned here, if you ever get a chance to testify and they ask your opinion.”

Thorpe looked at him.

“Before the embargo the North Koreans were shipping their military wares mostly to other friendly regimes in return for hard currency,” said Sanchez. “As we push the UN to tighten the screws on the embargo, all indications are that more of this stuff is going underground. Major weapons systems finding their way onto the black market and into the hands of people who don’t own territory or possess national flags. You want my opinion, embargos are not only weak because they’re hard to enforce. When you do enforce them, the result can turn out to be even more dangerous.”

“Unfortunately, we can’t resolve that one here,” said Thorpe. “It’s above our pay grade. For the moment let’s stick to the problem at hand. What are we dealing with? The device itself. How does it work? And what type of targets are most vulnerable? Let’s start with how it works.” He looked at Winget.

“In a nutshell?” said the officer.

Thorpe nodded.

“They use liquid high explosives in a vaporized form, mixed with delayed accelerants, in most cases aluminum powder or other flammable metal dust, magnesium, titanium, any of these will do. The bomb doesn’t kill or destroy in the conventional manner of most high-explosive ordnance, through fragmentation or shrapnel. It uses intense heat and massive concussion. It’s a two-stage process. On ignition the device will deploy a large volume of powdered flammable metal dust into the air. This is followed by the detonation of a superheated high explosive that creates the first of two pressure waves, in this case an out blast. A fraction of a second later, the powdered metal in the air will ignite, setting off the second and much larger pressure wave, this one called a back blast. It’s not unlike an implosion. This will collapse all but the most hardened structures and rupture the internal organs of anyone inside.

“Walls, even if they’re concrete, don’t provide much protection. The powdered metal, once it starts to burn, creates a superheated slurry that forms a molten plasma. This will find its way into even the smallest crevice in a wall and cook everything on the other side. If the target structure by some miracle stays intact and remains sealed, say an underground bunker or a hardened cave, the heat will suck the oxygen from it. So if the heat doesn’t kill and the initial blast doesn’t burst the lungs, the vacuum that follows will collapse them. If you’re in the target structure, it’s almost impossible to survive,” said Winget. “It’s a thorough and relentless killing machine.”

“What kind of delivery system would be required, say, for the item crated up in Thailand to reach and destroy its target?” asked Thorpe. “And please tell me it’s a heavy-lift airplane, something we can track on radar and shoot down before it reaches its target.”

“Aerial delivery might be optimal but not necessarily the only method,” said Winget. “In the proper setting a truck will do just as well. Unlike nuclear, you’re not looking for an air burst to obtain maximum effect. We used B-52s at Tora Bora with earth-penetrating ordnance because it was the safest and most efficient way to reach the target. You can use fuel-air bombs on the open battlefield, but that’s not the most optimum deployment. Maximum destruction and lethality would be obtained in a large enclosed structure. Thermobaric devices are perfect for underground bunkers, caves, tunnels, and they can be used to flatten large buildings. It’s most effective to get them inside the structure before detonation. Then again, McVeigh didn’t drive the truck into the federal building in Oklahoma City. He parked it at the curb in front. And we all remember the level of damage and loss of life there. So there are no hard-and-fast rules.”

“Let’s go back to the two men on the phone,” said Thorpe. “Any idea where that plane was going to deliver this thing, if it hadn’t gotten waylaid in Thailand?”

“Best bet’s Cuba,” said Sanchez. “They have airfields capable of landing and could provide cover for the device.”

“You think the Cuban government would allow an air attack on the U.S. from the island?” said Winget. “I don’t think so.”

“I didn’t say that,” said Sanchez. “But once it’s on the ground these guys could always transport the device by ship, move it from one vessel to another, and sooner or later it arrives in a U.S. port boxed as industrial tools and they could haul it by truck. You said so yourself.”

“Possibly,” said Winget.

“In other words, we don’t have a clue,” said Thorpe. “Mr. Sanchez, when your agency alerted the Thai government that there were arms on board that plane, I take it NSA had no idea that this device was there?”

“Correct,” said Sanchez.

“How did you know about the small arms?” said Thorpe.

“Communications intercepts and, from what I understand, some satellite surveillance.”

“What other agencies are already in the loop?” asked Thorpe.

“CIA and military intelligence branches have already been informed,” said Sanchez.

“What about Homeland Security?” asked Thorpe.

“I don’t know,” said Sanchez.

“We notify Homeland Security, the White House, U.S. Customs, especially at the ports. Tell them what to look for. Send them photographs if you can.”

Zink was taking notes. “We’ll need to tell the State Department.”

“Why?” said Thorpe.

“Just in case we’re not the target. Somebody’s gonna have to decide whether to inform foreign governments, and if so, which ones. What if the target’s in Europe, or the UK?”

“It’s not likely,” said Thorpe. “But okay, alert them, but ask them to keep it low-key and on a need-to-know basis only. I don’t want to be seeing it on CNN in the morning.”

“Homeland Security is going to want to know what the threat assessment should be. What do I tell them?” said Zink.

“Tell them what we know, the telephone intercepts and the nature of the device in Thailand. They’ll have to make a judgment call,” said Thorpe. He turned back to Sanchez. “If NSA can give us even a hint as to the identity of the two men on the phone, we need it yesterday.”

“Understood,” said Sanchez. “We did get voiceprints. We’ve got the computers checking for matches on overseas and domestic calls. If we get a match, we’ll try to nail down a location and turn it over to your people or the CIA to run it down, depending on where it is. Preliminary voice analysis indicates that the voice in Pyongyang displayed indications of a Slavic accent, possibly Russian. It was impossible to be certain since the entire conversation was in English. The other man appeared to be a native English speaker, possibly from Australia or New Zealand. He was very cagey. He kept trying to slip into a South African English Boer accent, but our analyst didn’t buy it.”

“Stay on it,” said Thorpe. He turned to Winget. “We will need all the satellite surveillance we can get over North Korea until this thing’s over.”

“We’re on it already,” said Winget.

“Any hint of these devices being moved or transported we need to know about it immediately,” said Thorpe.