“We’re ready,” Anika said.
“I’ll be damned, Chief.” Mercer grinned, momentarily overcoming his uneasiness. “You actually did it. You got this thing going.”
“Don’t thank me. Wolfgang Rossler’s the man we owe our lives to. If the Nazis had had a few more like him, they could have won the war on maintenance alone.”
When it was time, Mercer gave the order to raise the bow planes to reduce their depth. Ira asked if he should vent water from the tanks, but the log indicated that this maneuver was done only with the planes. After another five minutes the tunnel took its first turn to the right.
“Marty, steer right ten degrees. I’ll tell you when to ease off.” This was a shallow turn in what the chart said was the widest part of the passage. Mercer wasn’t concerned about hitting anything yet. That fear would come later. He watched the compass next to him. “Okay, ease her back. A little more. That’s it.” He let out a breath. “Increase to one hundred and thirty revs and prepare for a hard turn to port in two minutes.”
They were well inside the sunken conduit, surrounded on all sides by rock and ice. A miscalculation in any direction would kill them all. No one knew if the tunnel was still wide enough to allow the sub passage, so they were forced to crawl along blindly, unable to reduce their speed because of the chlorine gas filling the bilge.
“Marty, coming up is a ninety-degree corner, so bring us to port as fast as you can spin the wheel. Now! Anika, ten degrees down on the planes. Make your depth eighty meters.”
“That’s two hundred and fifty feet,” she said. “Can this old hull take it?”
“We’ll know in a minute.”
Creaking like a sailing ship caught in a typhoon, the U-boat spiraled deeper into the abyss. Her moans reminded Mercer of whale song. “All right, straighten her back out. Reduce RPMs to one hundred. We’ve got a long stretch at this depth. Make sure she doesn’t drift.”
Like steel nails drawn across a chalkboard, the U-boat scraped against the side of the tunnel. The impact made them clutch their seats. The sub veered away from the wall and then drifted back again, harder, the hull plates screaming. Dislodged rocks hit the hull like cannon fire.
“Shit! Marty, bring us to starboard two points.” The unholy screeching died as soon as Bishop spun the wheel.
“What happened?” Erwin cried. He’d run into the control room at the first impact, too scared to remain in his bunk despite his claustrophobia
“We needed to scrape some barnacles off the side of the boat,” Mercer replied. “We should be back in our lane again. Marty, bring her back to eight degrees magnetic.”
“You did take the North Pole’s drift into account, didn’t you?” Bishop asked.
“And the fact we’re moving with the current, which according to the chart runs at two knots.”
They continued on this course for twenty minutes when Erwin, who was at the back of the control room, began to cough. Mercer looked over his shoulder and saw a sickly green mist rising from the engine room behind him. Chlorine gas. The first tendrils seemed to wrap around Erwin’s stooped form like tentacles of some wrathful creature.
“Hold out for as long as you can before using the air tanks I rigged,” Ira reminded.
Mercer got his first stinging taste of the chlorine. His eyes burned. They had another fifty minutes before they reached the open. It was going to be close. In order to protect their vision, everyone donned the protective goggles they’d used to combat the arctic weather.
“The tunnel floor’s about to rise,” Mercer said. “Prepare to blow tanks to bring us to fifty-five meters, ten degrees up on the plane. Marty, we’ve got a quick series of turns coming up, port, starboard, port. You just turn the wheel when I tell you. Increase to one hundred and thirty RPMs again when we level out.”
They went into the turns at the increased speed, the old sub tilting first one way and then the other on Mercer’s commands. He didn’t tell them that the channel through the S-turn was just wide enough to allow the maneuver.
The tail slammed into a rocky pinnacle coming out of the first curve, slewing the boat like it had been torpedoed. Mercer’s call for a quick correction wasn’t fast enough. They went into the second turn and the bows veered into the rock face, reverberations booming like the inside of a church bell. Erwin shrieked and Anika’s knuckles whitened on the plane control wheel.
“We’re doing fine,” Mercer said, choking when he took a lungful of gas. “Marty, bring us to port, bearing ninety degrees.”
Marty nodded, unable to speak around the accordion tube from his air cylinder. The hull creaked.
Mercer didn’t understand what had happened. The chart said that they shouldn’t have hit anything that second time. The pipe was supposed to have widened. The next turn was in five minutes, and he wasn’t sure if they were traveling in the middle of the passage or along one side. They didn’t have the luck to consider they were in the middle, so Mercer had two choices. Were they far left or far right?
The control room was filled up to their knees in heavy chlorine gas, wisps rising up like fog from a haunted moor.
“Marty, are you right- or left-handed?” Mercer asked and finally started drawing breath from his own cylinder. Marty held up his left hand. “Bring us two points to starboard for a minute and on my command crank us to port.”
If Mercer’s guess was wrong, they would plow straight into the far side of the turn at roughly six knots. That kind of blow would crumple the bow like aluminum foil. “Helm, steer us to one hundred and thirty degrees.” Everyone felt the tension in his voice.
Angled over so they had to brace themselves, the sub went through the turn, gas pooling against the bulkheads like a liquid. Mercer held his breath. They all did. The beat of the propellers through the water sounded like a distant drumroll. By Mercer’s watch they were halfway through the turn. He checked the chart and lurched. The bottom of the tunnel had dropped away and the ceiling had lowered. They were supposed to be at seventy meters!
“Dive!”
Ira twisted open valves to flood the bow ballast tanks at the same time Anika and Hilda cranked the dive planes as far as they could go. The sub seemed to stand on its nose, loose articles crashing to the deck all along the length of the vessel. Mercer’s feet came out from under him and he swung free, dangling from a steel pipe.
They didn’t quite make it. The top of the conning tower crashed into the underside of the subterranean channel, ripping away both periscopes in a wrenching squeal of torn metal. Water flooded the attack center located in the sail and would have filled the ship if it weren’t for one more watertight hatch. A wall of chlorine gas as dense as smoke raced down the boat, cutting visibility to almost zero until Anika brought the bow back up, leveling her out at eighty meters just as her keel began to scrape the bottom. The noxious cloud settled again, reaching up to Mercer’s waist.
“Bring us to seventy meters. Ira, neutral buoyancy again.” Mercer checked the compass and saw that Marty had them perfectly on course. “Good job. That was my fault. Sorry.”
Mercer paid for complimenting them. Seared by gas, his lungs went into convulsions and vomit shot from his mouth. He sucked great drafts from his air bottle, cleansing the tortured tissue. They had only one more change of depth to clear a peak in the channel and fifteen more minutes to go.
He knew they wouldn’t last that long. Marty had been on his bottle much longer than he had, and Mercer could imagine poor Erwin had been hyperventilating since they’d left the cavern. He changed the figures on the chart, making a quick guess rather than an accurate calculation. “Maximum revolutions!”
The tachometer peaked at two hundred twenty RPMs. “Bring us to thirty meters on my mark.” Mercer could feel the sub racing along the bottom of the tunnel, careening toward a bump on the seafloor that rose nearly a hundred feet. Come up too soon and they slammed into the ceiling of the passage. Too late and they would barrel into the mount. “Ten degrees up on the planes. Mark!”