Glass had already stepped up to the periscope stand. Durand was still looking through the scope, tracing a circle, watching for anything that might be approaching the sub. He leaned back from the scope for a second and rubbed his eye. “What now, Skipper? Go deep?”

“No, Mr. Durand. Surface the ship. We’re heading for port.”

Durand looked hard at Glass. “Did you say surface, sir?”

“That’s what I said, Mr. Durand. Now get a move on it. We don’t have time to lollygag around out here.”

Ten minutes later the sub was surfaced, ready for the long, cold run on top of the ocean all the way into Faslane.

O’Malley stepped into the control room. He looked like a bright orange version of the Pillsbury Doughboy. The exposure suit he had donned was bulky and not very fashionable, but it was warm, waterproof, and floated should the wearer fall overboard, so no one complained.

“Request permission to open the upper hatch,” he called across the room to Durand.

“Open the upper hatch, one inch pressure in the boat,” Durand sang in response.

O’Malley bounded up the ladder. In a few seconds there was the unmistakable sound of air whistling past the partially opened hatch. Glass felt his ears pop from the pressure change just as he saw the HATCH SHUT light on the ballast control panel flash out. The wind rushed out of the boat as the air pressure inside equalized with that outside. In a few moments the whistling stopped. O’Malley swung the heavy hatch fully open and climbed up into the dripping-wet bridge cockpit.

Glass donned his own exposure suit and made the long climb to the bridge. The wan sun hung low on the horizon like a dim afterthought, a pale orange ball in the otherwise gray winter sky. This far north and this time of the year, it appeared above the horizon for a few hours each day, bringing scant warmth to a cold, dreary place. A bitter wind whipped the sea into whitecaps with the occasional gust sending bullets of spray against the Plexiglas windshield.

“Where to, Skipper?” O’Malley yelled over the wind as Glass emerged from the hatch to stand next to him in the cockpit.

“Steer zero-nine-zero until you get to the North Channel. We’ll come to one-three-zero then until we’re clear of the Mull of Kintyre. By then Nav will have charts plotted so you can see what’s going on. Now kick her up to a full bell. We need to get moving.”

Toledo picked up speed until the sea washed back across her bow, deep and clear until it crashed high up on the sail, then falling in frothing white chaos. A broad white churning wake stretched far behind as the sub plowed ahead through the winter sea.