Nasiji weighed the pieces on a digital scale beside the box, first one by one, then all together. Thirty-two kilos—seventy pounds—in all. Nasiji stared at the scale, a muscle twitching in his jaw, a vein pulsing madly in his forehead.
“We’ll work it out,” Bashir said. “We’re close.”
But Nasiji didn’t respond. Until, finally, he put the pieces back into the box and ran his hands through his hair and smiled. His change of mood was as disconcerting as his fury had been.
Were you pretending to be crazy then,
Bashir wanted to ask,
or are you pretending to be sane now?
But he supposed he knew the answer. None of them were sane. How could they be? They were building a nuclear bomb. In a stable.
Is this right?
For the first time since he’d gotten involved in this scheme, that simple question came to Bashir. Was it his place to kill hundreds of thousands of Americans, the same Americans he tried to save on the operating table?
Then he thought of his uncle, in that awful prison at Tora. Egyptians had killed him, but the United States was responsible. The Americans were the puppetmasters all over the Muslim world. Saddam Hussein had been one of their puppets, too. As long as he did what they wanted, fought wars against the Iranians, they didn’t care what he did to his people. But when he stood up to them, they came after him. This place, the United States, had killed millions of Muslims. A bomb like this was the only way to stop them, to even the score. It wouldn’t be pretty, but no war ever was. So Bashir forced the question out of his mind.
He hoped it wouldn’t come back.
THE IMAGE PLAYED
over and over in Nasiji’s mind, a video he couldn’t turn off: the crate falling out of the lifeboat and sinking into the Atlantic. If only they’d held on to the second bomb. Instead . . . when he looked at the numbers on the scale, he couldn’t help but feel as though the devil was working to thwart him.
Again he gathered up the pieces and scattered them on the scale and looked at the black numbers staring at him: 32.002 kilograms. The Russians had been precise, he’d give them that.
“Thirty-two kilos,” Yusuf said. “What does that mean?”
“It’s not enough, that’s what it means.”
“Please, Sayyid,” Yusuf said. “I know you explained before, but if it works for the Russian bomb, why do we need more?”
“Yusuf—”
“I’m just trying to understand.”
“The secondary, the bomb we took apart, the pieces fit together into a globe, right? And when the first bomb, the primary, goes off, the secondary gets smashed together, becomes
supercritical
”—that word in English.
“Super-critic-al?” Yusuf sounded like he was auditioning, badly, for a part in
Mary Poppins.
“I told you before. Supercritical means the explosion is speeding up, more and more energy is being released. The Russians, the Americans, they’ve figured out how to smash the material very fast, and that means they need less material to cause an explosion. Ever since the 1940s, we’ve known this is how it works.”
“But we can’t smash it together as fast as they can.”
“That’s right. The gun that we’re using, it will shoot the uranium piece at four hundred meters a second”—a quarter-mile a second, nine hundred miles an hour.
“Isn’t that fast?”
“Compared to how quickly the fission reaction happens, it’s slow. So we need more uranium, a bigger sphere, to make sure the bomb will go off.”
“But if it’s so complicated, why don’t we use the Russian bomb?”
“I should just go back to Iraq, leave this to you.”
“Sayyid—”
“I tell you again. The secondary won’t go off without the primary. And the primary, I promise you, it’s been engineered so it won’t go off unless it’s been properly armed. With those famous codes. And we can’t use our own explosive to set it off either. You can’t just paste dynamite around those bombs and push a big handle. The explosive has to be placed and detonated just so, or the bomb won’t go off. We don’t have the equipment. Synchronous detonators and high-grade explosive and a lathe that can cut to the tolerances we need. And even if we could buy them, I don’t know if we have the skill to use them. It would take us six months practicing and testing to be sure. You want to live here for six months, hope no one notices?”
Nasiji pointed at the recoilless rifles stacked against the wall. “The kind of bomb I want to make, it’s so much easier. Mold the pieces into the right shapes, two masses, both just subcritical, fire one at the other. As long as you have enough material and you fire it fast enough, it’s certain to work. With sixty kilos, it would have been a joke. We could have done it in a week. Now . . .”
“But isn’t there a half way?” Yusuf said. “We have half as much material as we wanted. Can’t we make a bomb half as big?”
“That’s not how the physics work,” Nasiji said. “Trust me.” Why hadn’t he found a way to detonate the bomb they’d stolen, instead of leaving himself in this mess? Why hadn’t he listened to Bernard and Bashir and sent the bombs to New York on a container ship, instead of being tricky and sending them through Newfoundland? Why hadn’t he made sure that both crates were properly locked down in the lifeboat? He was so stupid. He had failed his father, failed his family, failed his people. His father . . .
He felt his anger build again and walked out of the stable and into the cold night air. He leaned against an oak tree and craned back his head and looked through the naked branches at the stars, the ultimate nuclear-power plants.
Away from the scale’s figures and Yusuf’s questions, his stomach began to unclench. He was being too hard on himself. Thirty-two kilograms was a massive amount of enriched uranium, more than anyone outside a weapons laboratory had ever seen. Little Boy had been sixty-four kilos, but Little Boy had been made from 80 percent enriched uranium—not nearly as pure as the material they had. He hadn’t tested these pieces yet, but they were surely 93.5 percent enriched, standard weapons-grade.
At that level of purity, even a simple sphere of uranium, with no reflector, no compression, would go critical and produce a nuclear explosion at a size of about fifty kilograms. They were short, but they were in the ballpark.
Nasiji wondered if Bernard could somehow deliver the beryllium without getting busted. Doubtful. But even without beryllium, they could try a steel reflector. Steel wouldn’t be as effective as beryllium, but it would help. Maybe a double-gun assembly, to achieve maximum acceleration, if Yusuf and Bashir could somehow handle the welding.
With thirty-two kilograms, putting this bomb together wouldn’t be easy. But it might not be impossible, and he knew the tricks. Slowly, over sixty-five years, first the physics and then the engineering details of building these bombs had leaked out.
Yusuf emerged from the stable, walked up to him tentatively.
“Sayyid, I must say this. I’m sorry for my stupid questions. It’s confusing, that’s all.”
“It’s I who should apologize,” Nasiji said. “My temper—”
“And I wanted to say, if it’s really impossible with this much, we’ll get more. We’ll leave this here, go back to Russia, find another martyr.”
Nasiji smiled at the stars. He couldn’t help but admire Yusuf’s attitude, though they couldn’t get within a hundred kilometers of a stockpile now.
“No need, Yusuf. We’ll make do. I have some ideas.”
“Is it possible?”
“God willing. We’ve come too far to quit.”
THE NEXT MORNING,
Nasiji took his physics and engineering textbooks and a sketchpad and Bashir’s laptop and shut himself up in the farmhouse basement beside the Ping-Pong table. Bashir tried to follow, but Nasiji shooed him away.
“Tell Thalia to leave my lunch at the top of the stairs. Dinner too, most likely.”
“You don’t want help?”
“Not for this.”
“All right, Sayyid. But you’re going to see us anyway.”
“Why’s that?”
“There’s no toilet in the basement. Unless you plan to bring down a bucket.”
At first, Nasiji spent hours sketching out possible ways to set off the plutonium primary inside the Iskander. After all, as Yusuf had pointed out, they already had a bomb. Why not use it? But finally he gave up. He couldn’t figure out a foolproof way to trigger the explosives attached to the bomb, and creating a new trigger, though theoretically possible, would take too long.
That night he went back to his original plan, the gun-type uranium bomb, the Little Boy design. One piece of enriched uranium was molded into a piece that looked like a length of pipe. A second, smaller piece was shaped into a solid cylinder that fit snugly within the larger piece. Both pieces were subcritical, meaning they were each too small to detonate on their own.
The solid cylinder was placed at the end of the gun barrel. Then the pipe-shaped piece was shot at it, creating a single piece that contained a supercritical mass of uranium, big enough to set off a nuclear explosion. The Americans had placed a neutron initiator, a few grams of beryllium and polonium, at the center of the bomb to make sure the detonation happened on schedule. But the initiator wasn’t strictly necessary. The uranium would detonate on its own even without it. As Nasiji had told Yusuf, the great virtue of the design was its simplicity. If the bomb came together quickly enough and had enough uranium, it couldn’t help but go off.
What Nasiji hadn’t explained to Yusuf was that placing metal around the uranium core would make the explosion happen more efficiently, thus allowing the use of less uranium. The metal was called a reflector, because it bounced the neutrons, causing the chain reaction back at the exploding core. Beryllium was the ideal material for the reflector. A sphere of uranium surrounded by beryllium could produce a nuclear explosion with as little as sixteen kilograms of uranium—a critical mass less than one-third that of an unreflected sphere.
So, as an insurance policy, Nasiji had asked Bernard six months ago to try to get a cache of beryllium. But Bernard had reported back that the stuff couldn’t be had, not without taking a huge risk, possibly alerting the German authorities. Nasiji had told him to back off, not push too hard. With two warheads, Nasiji figured he would have enough material to make a bomb of his own.
Now, though, they were short of uranium. Beryllium was the shortest route to making a full-sized bomb. Nasiji had asked Bernard to try again. And only yesterday, in a coded e-mail message, Bernard reported he’d made contact with a man who might be able to provide the stuff. But Nasiji wasn’t at all sure Bernard would come through. In the meantime, they’d have to plan on using a simpler material, something they could pick up in Rochester or Buffalo without attracting too much attention. Tungsten carbide would probably be too much for Bashir to forge. In the end, steel would probably have to do. With that thought, Nasiji spent several hours calculating the optimal thickness of a steel reflector.
The calculation was complex, but the necessary variables were available: the neutron multiplication number for steel, the average number of collisions before capture, the likelihood of a neutron emerging from a collision. He found in the end that the tamper ought to be about twenty centimeters thick—about what he would have guessed before he’d done any of the math.
Finally, he designed the uranium core and the steel tamper around it. Basically, the bomb would look like a cannonball with a hole on the top. They would weld the artillery barrel into the hole and then fire the uranium plug down the barrel into the hole. The plug would slide over the uranium core in the middle of the barrel, and—
Boom.
At 3 a.m. that night, Nasiji was done. He had a basic design, not fancy, but a start. Bashir and Yusuf could get to work forging the molds for the reflector and the core.
WHEN NASIJI EMERGED
from the stairs, blinking in the light of the kitchen, he expected to be alone. But they’d waited up for him. Tried to, anyway. Bashir dozed on a rickety wooden chair, a half-eaten plate of hummus and baked chicken on the table before him. Yusuf curled up on the rug under the kitchen table.
They jerked up as he walked in.
“It’s done,” Nasiji said.
“What’s done?” Bashir said, running a hand across his mouth to wipe away the sleep.
“I’ve finished the design.”
“But . . . you said last night it wasn’t possible.” This from Yusuf.
“I can’t guarantee it will work. We’ll see.” Over and over, Nasiji had run the numbers, tried to calculate whether the thirty-two kilos they had would be enough for a chain reaction inside a steel reflector. But the equations required a level of detail about the subatomic properties of iron and uranium that he didn’t have, and the math got messy. Forty kilos would be enough, he was sure. Twenty wouldn’t. Thirty-two? They wouldn’t know until they pulled the trigger.
24
A
solid bronze knocker shaped like a lion sat in the center of the front door of Bernard Kygeli’s house. Wells swung the knocker against the heavy black wood, picked it up and clanged it again.
“Hullo! Anyone home!” he shouted. “It’s Roland.”
“Ja?”
a woman’s voice said. Then a few questions in German. A woman’s face, framed by a headscarf, peeked out at Wells. He was dressed for the occasion, holding a briefcase and wearing black gloves and a new gray suit he’d bought at the fancy department store downtown.
“I don’t speak German.
Sprechen Deutsch nicht!
And I’m freezing my stones off out here.” Wells was hardly exaggerating. For days, the weather in Hamburg and Warsaw had been miserable, a hard wind driving sheets of rain and sleet horizontally through the streets. Wells knocked again, hard. “Stupid woman. Is Helmut home?”
“Helmut?” The door opened a notch, revealing a middle-aged woman who wore a long-sleeved jacket that was tailored, black with gold filigree, modest but stylish. Wells put his shoulder to the door and popped it open. Its edge caught the woman and she stumbled back and dropped to a knee. Wells stepped inside and shoved the door shut. The woman yelled at him in German, less frightened than angry. He pulled her up, a hand under her elbow, and put a finger to his lips.