The helo made it over the taffrail and hovered over the hangar deck.

It was ten feet from touchdown when the ship slammed down into the sea and the deck slid out from beneath it. The superstructure of the ship stopped shielding the helo from the wind and a good forty-knotter caught her upside the head. Whoever was driving wisely decided that discretion was the better part of valor and hit the throttle, roaring off to port, circling around, and coming up again on the stern.

Sara crouched down behind the cowling, the force of the wind threatening to pull her hair out by the roots, and worked at reswallowing her heart. The LSO was crouched against the exterior of the hangar. “You okay?” he yelled, or she supposed he did. She saw his lips moving, but she couldn’t hear him over the wind, the all ahead full the Sojourner Truth had going on. She gave him a thumbs-up, and then they both heard the second approach of the helo and he duck-walked forward to stand in front of the hangar and guide them in.

She could hardly bear to watch, but this time they plunked her down right in the gold, in the exact center of the circle painted on the hangar deck. Sara scuttled around the hangar, dragging her knuckles like an ape, and yelled in Ostlund’s ear, “They’ve got a passenger the captain wants to see pronto.”

He nodded and followed the rest of his deck crew forward, hunched over so the rotor wouldn’t take their heads off. He reached the helo and slapped the side. She could see Sams, in the left seat, crack his door. Ostlund yelled at him. Sams nodded. The LSO walked around the front of the helo and disappeared. Through the windscreen Sara could see the helo’s aft door slide open and someone step to the deck.

Ostlund came scrambling back around the helo on a heading for Sara, followed by someone tall bundled into a Mustang suit and a watch cap pulled low over his brow.

“This here’s our XO, she’ll take you to the captain.”

“Thanks.” The man unbuckled his helmet and turned to Sara.

Her jaw dropped.

“Hi, Sara,” Hugh said. “I need to talk to your commanding officer. Now.”

The ship heeled suddenly and hard to port, and everyone staggered to regain their balance. There were shouts and curses from the hangar deck as the deck crew hung on to the helo’s tie-downs. With a great sense of foreboding Sara looked around to see that the next storm had indeed come upon them. Blowing snow needled into her exposed skin. The seas were rising, and the wind howled around the ship like a hungry wolf.

“Follow me,” she said to Hugh, and then had to yell it again so he could hear her over the sound and fury of the storm.

“ALL RIGHT,” LOWE SAID.

They were in the wardroom. Lowe sat at the head of the table facing Hugh, who stood opposite him at the table’s foot in front of a dry board which was covered with an outline of names, dates, and places. On the captain’s left were Sara, Ops, and the Engineer Officer, a tall, pencil-thin young man who could barely find his way to the bridge but who could disassemble a Caterpillar generator and put it back together again blindfolded. On the captain’s right were Ensign Ostlund, Ensign Ryan, and Chief Mark Edelen.

“You want us to believe that a North Korean terrorist-no, two-have built themselves a backpack bomb filled with radioactive material, loaded it into a mobile missile launcher, which they have then smuggled on board an oceangoing vessel, and are currently attempting to sail it into these waters, for the purposes of aiming the weapon at a target in Alaska, which you have been told by a less than reliable source to be one of the military bases, Elmendorf or Eielson. Why not Valdez, by the way? The oil terminal ought to go up with a bang big enough to keep any terrorist happy.”

Hugh met the captain’s sarcasm with the same stoicism he had displayed for the last hour. He held a black marker, the cap of which he repeatedly clicked on and clicked off. Click, click. “First of all, sir-” Hugh was respectful but firm. “A backpack bomb is generally held to be nuclear, and, uh, well, in a backpack. I don’t think that is the case here.”

“Really? What is it, then?”

The ship rolled over a swell and Hugh took a quick step to keep his balance. “It’s a dirty bomb. Instead of a weapon of mass destruction, it’s called a weapon of mass disruption.”

Sara, watching the captain out of the corner of her eye, saw him take a deep breath, and wondered what room on board she could convert to a brig when the captain finally lost his temper and ordered her to throw Hugh into it. “What’s the difference between the two?”

“What’s most important to a terrorist is that the weapon of mass disruption is a lot cheaper to make.”

“More bang for your buck, eh?” the captain said.

Hugh didn’t make the mistake of smiling at this almost genial query. “Partly, sir. There is also the fact that fissile, that is, weapons-grade uranium and plutonium are much more closely controlled and monitored than radioactive materiel.”

“Like cesium.”

“Like cesium-137, yes, sir. Cesium-137 is an isotope used in medical procedures like radiotherapy. It’s relatively easy to get, and much cheaper to buy in bulk than weapons-grade uranium.”

“Or plutonium.” Yes, sir.

The ship rolled. Hugh hung on to the edge of the dryboard, waiting for the ship to regain the vertical.

“What’s it look like?”

“Talcum powder.”

“Handy,” the captain said. “You could hide it in an Old Spice bottle.” Yes, sir.

“But you don’t think they’re hiding it. You think they’re about to use it.”

“Yes, sir.” Click, click.

“Based on nothing but a lot of circumstantial evidence.”

“A lot of what I do is connect the dots, sir.”

The captain didn’t rush to contradict him, but Sara knew he would be marginally impressed by this frank admission.

“But if you connect these dots”-Hugh pointed at the dry board- “you’ll see that in this case there is enough circumstantial evidence to warrant concern. The intelligence accumulated about North Koreans trained by al-Qaida in Afghanistan. Recovery of blueprints for such a bomb from the al-Qaida caves. The report of the sale of enough cesium-137 to build such a bomb. Much more than necessary, actually, my informant said that-”

“How much is enough?”

“Less than two ounces, sir.”

Sara, watching the captain because she didn’t want to look at Hugh, saw him trying to hide his shock. “How is it detonated?”

“A couple of pounds of dynamite will get the job done.”

The officers exchanged glances. “You are talking about a piece of ordnance that could fit into a shoebox.”

Hugh thought about it. “Not much bigger than that, sir, no. Easily loaded into the warhead of a missile.”

“A missile that can be launched by a mobile missile launcher.” Yes, sir.

“Like from a ship.”

“Like from a ship, sir, yes,” Hugh said.

Ryan cleared his throat. “If I may, Captain?” The captain nodded. “Mr. Rincon, you’re going to need a pretty heavy ship to carry a missile launcher, and an even heavier one to launch it without sinking the ship that is carrying it. The force of the thrust generated by the fuel upon liftoff would crack the spine of your average freighter.”

“I don’t think they care if they sink their ship, Mr. Ryan. I think they only care about delivering the weapon and wreaking as much death and destruction as they possibly can. These aren’t soldiers we’re talking about here; these are terrorists.”

“Do they have a missile launcher, Mr. Rincon?”

“They bought one, Captain. At the same time and through the same dealer as the cesium-137.”

The phone rang. Sara answered it. “Wardroom.”

“XO, I-”

“Is the ship sinking?”

“Uh, no, but-”

“Then not now, Tommy.” Sara hung up.

“As I said before, sir,” Hugh said respectfully, displaying a heretofore unknown-at least to Sara-talent for soothing the savage breast of command, “terrorists don’t think in terms of big bangs. They think in terms of numbers of people killed, and of television footage broadcast worldwide of those people in body bags laid out in rows. The more rows the better. A weapon of the sort I have just described will destroy Elmendorf, and a city the size of Anchorage along with it.” Click, click.