“Where are you going?” Hilda Brandt whispered.
Anika swallowed an unexpected jolt of guilt. “I have to pee.”
“The toilet is behind you past the wardroom,” Hilda reminded with a trace of humor in her voice. The chef knew where she was going.
Thankful for the dark because her face was flushed with embarrassment, Anika turned and padded to the bathroom.
“Better?” Hilda teased knowingly when Anika returned to her bunk.
“No.”
The first explosion came a little past seven the next morning. Mercer was alone at the chart table, cleaning Cosmoline from the pair of MP-40 Schmeisser machine pistols he’d found in his cabin along with a broom-handled Mauser — a pistol that had been an antique even when the sub was built. He’d already checked and matched the ammo. He looked upward as if he could see through the hull and the water. Not that he needed to see to know what was happening. “Garbage dump,” he said. At the second rumble he added, “Slave area.” The third would be the excavation that was already partially blocked, and then came the longest detonation, a rolling thunder that went on for five minutes, amplified by the acoustics of the cavern, the lagoon, and the U-boat. The main access tunnel had just come down, blasted into an impenetrable wall of rubble by explosive charges. Working around the clock the Germans had completed their task and sealed the cavern forever.
“What the hell was that?” Ira charged into the control room from the radio shack, where he’d been attempting to fix the wireless or the sonar gear. He’d had no luck with either.
“Gunther Rath burning his bridges, Chief,” Mercer replied passively. He’d started teasing Ira by using his former rank during their days of training. “We’ll give it an hour or two to let the dust settle and then surface the boat.”
“They’re gone?”
Mercer nodded. “Unless a few had a death wish.”
In a swirling vortex of air bubbles, the U-boat rose from the bottom two hours later, black water streaming off her outer hull. Erwin Puhl was in the conning tower and he threw open the hatch, not caring about the torrent of water that doused him. Although the cavern was pitch-black, he took the first deep breaths he’d enjoyed since losing the use of the periscope.
“How’s that?” Mercer asked from below.
“Heaven,” he sighed, fingering water from his glasses.
Within a few minutes, Ira fired the port diesel. The engine ran rough from fuel contamination and tar-thick oil, but he felt he could keep it running long enough to reach Iceland. Mercer went ashore to check the cavern, finding it much as he’d predicted. There was no evidence that anything man-made had ever been in the chamber, and all the alcoves were blocked with debris. Boulders and loose rock from the entrance tunnel spilled far onto the main floor, indicating a great deal of its length had been dynamited. He was confident that Rath and his men had collapsed a similar amount of the tunnel near the surface.
If they couldn’t negotiate the sub through the zigzagging underwater channel, they would die here in the darkness. He returned to the U-boat to help Ira fill the battery cells with acid. Once they recharged — if they recharged — they would be ready to leave.
After an hour of noxious work in the cramped aft battery room below the galley, Ira announced that they were in trouble.
“Considering our circumstances, you’re not telling me anything new.” Mercer’s eyes streamed tears from the caustic fumes.
Lasko’s normal humor had abandoned him. “I mean real trouble. Most of these batteries are worse off than I thought. The ones taking a charge leak like sieves. Once we close the hatches, the sub’s going to fill with chlorine gas a lot faster than I anticipated.”
Mercer tensed. “How long do you think we can stand it?”
“Depends on the individual. But after an hour or so the boat’s gonna be a coffin ship.”
“Can you rig some breathers for us?”
“I can, but that’s not the problem. With acid eating into the functioning batteries, the boat’s electric motor will lose power long before the first of us checks out. Have you figured out how long it takes to get through the tunnel and out to open sea?”
Mercer’s expression darkened. “According to the captain’s log, about an hour and a half.”
“Figures,” Ira said sourly.
“All’s not lost. All we have to do is push our speed over what he wrote to shave off some time. It won’t take me long to make corrections in the timing of our turns to compensate.”
“You’re forgetting that his figures are based on traveling a certain amount of time at certain RPMs before making a turn. Back then his boat was loaded with stores and a crew of fifty. We’re at least a hundred tons lighter, which will make us faster. I can double the RPMs but that won’t necessarily mean that you can halve the time.”
“I hadn’t thought of that,” Mercer admitted. “Any suggestions?”
“Factor in a speed difference of about half a knot faster than the captain used and hope to Christ you’re right.”
“What do you mean ‘hope I’m right’? It’s your idea.”
Ira smirked. “I don’t want the others blaming me when we plow into a tunnel wall because we missed a turn.”
It took a further two hours to get ready. Once the batteries were charged and any electrical faults repaired, Ira made certain that the air tanks were topped to their maximum pressure tolerance. Using the diesel, they swung the antique away from the pier and lined up with the entrance to the submerged channel out of the cavern. Hilda and Anika would operate the planes while Marty was at the helm to control the rudder. Ira had stationed himself at the ballast control. Mercer stood at the plotting table, where he could watch the gyrocompass. On the table were a pair of dividers and the captain’s log, which lay open to the chart of the submerged passage. The rough sketch of the tunnel showed a twisting tube filled with numerous obstacles the sub would have to avoid as it wormed its way to the outlet in the fjord.
“We’re in position,” Erwin called from the conning tower. He had noted their distance off the dock using the attack scope’s range finder.
“You know what you have to do,” Mercer shouted back up to him.
The scope sank back into its mount and a second later Erwin sealed them in. This time he actually walked calmly to the bathroom and had time to close the door before he began retching.
Without the pounding throb of the diesel, the boat was remarkably quiet.
“Chlorine gas is already starting to build up,” Ira said, though it would be a while before they would smell it.
Mercer consulted his chart, noting how sharply the cavern floor had dropped off from the pier. “Ira, make your depth sixty meters. Helm steady. Planes at neutral.” Mercer thought he sounded like an actor in an old war movie, but his crew responded to his orders without question.
“Hold there, Ira,” Anika called, her eyes riveted to the fathometer at her station.
“Gotta tell me earlier or else we’ll sink past our target depths,” Ira said, compensating for the mistake.
“Aye, aye. Okay, depth sixty meters.”
“Here we go, boys and girls.” Consulting his revised propulsion figures, Mercer spoke crisply. “Give me ninety RPMs for ten minutes starting” — he checked the ratcheting second hand on his TAG Heuer — “now!”
Silently the U-boat began to creep across the lagoon, a washing hiss sounding through her hull as she cut the water. “I’ll need two degrees up on the planes when I give the command in about five minutes.”