“They’re up to something,” said Carlson. The Alliance had basically two categories of countermeasures, things that spun in the water, and things that fizzed; they looked to be using both. The goal for both was to create a large acoustic cloud that the Polaris could escape behind, the same way infantry used smoke grenades on the battlefield. Carlson wasn’t too worried; she had too many good cards in her hand. But she was curious.
“Target zig,” said Reese, her youngest officer, on the phones with sonar. “Target has turned to the south,” he said, taking the information from the display in front of him.
Carlson looked at the plot. Over days, the ship, despite all its maneuvering and attempts to evade them, had steadily made its way toward Eris. Maneuvers like this weren’t unusual as they tried to shake her. But the countermeasures were a new twist; the large amount of ambient noise they were creating was weakening the acoustic grip they held on their prey.
She walked over to the sonar display, the narrow band readout stacking dots on top of each other. The dots represented the actual data from sonar. If they stacked in a perfectly straight line, it indicated that they had a good-quality solution: they knew the Polaris’s course and speed. But the newest dots were starting to stray, bending toward the right.
“Target is speeding up, too, no?” she asked.
“Yes, Captain,” said Reese. “Turned to starboard and sped up.”
She clicked on the screen and looked at the data. The 60 Hz tonal was loud and clear. But the clicking of the reduction gear had disappeared entirely.
“Ship is rigged for silent running,” said Moody. She was looking at an electronic status console in front of her. All unnecessary machinery had been stopped to make the ship even quieter. This included fans and air conditioners, so the temperature was steadily climbing in control. They were all at their battle stations. The doctor was in sick bay, “counting Band-Aids,” as he said. Frank was in the torpedo room, while Ramirez was in the engine room. The captain, Pete, and Moody were in the control room. Pete was in the dive chair, directing the rudder and the stern planes. “Countermeasures are in the water and activated.”
“Very well,” said McCallister. “Launch the MOSS.”
They felt nothing in their feet, no rush of water or change in pressure — it wasn’t like when a torpedo was ejected from the ship. They had pumped open the outer doors of the torpedo tube, and the MOSS simply swam out.
“The MOSS is launched,” reported Moody.
“Very well,” said the captain. “All stop.”
Pete rang it up, and the engine room answered immediately.
“Left five degrees rudder,” said the captain. Pete turned the yoke in front of him. “Sir, the engine room has answered all stop. My rudder is left five degrees.”
“Very well,” said McCallister. “We’re turning away. How long until the MOSS broadcasts?”
“Five minutes,” said Moody.
Everyone in the control room looked at their watches.
The MOSS swam from its torpedo tube powered by a small electric engine. Unlike the ship it was born to imitate, its propulsion machinery was almost silent, the energy flowing from a chemical battery rather than the spinning of turbines and the pumping of water through a nuclear reactor. Five minutes into its journey, it began broadcasting a recording from a transponder in its nose. The sound was carefully designed to sound like a Polaris submarine, with a 60 Hz tonal and a broadband signature in the back of that like the whooshing of steam through pipes. While the MOSS was tiny, it was noisy, purposefully so, creating an acoustic profile that was slightly louder than the ship it was leaving behind. It was a decoy, and like a hunter’s wooden duck floating on a lake, it had to attract attention without being obvious.
After five minutes of broadcasting, the MOSS turned on its programmed course. It turned right and sped up slightly, to 8 knots. Its acoustic twin, the real submarine, turned left at this same time, and the distance between the two grew.
After forty-five minutes, its battery exhausted, the MOSS died. A small valve slid open, filling a center chamber with seawater. Its mission complete, the MOSS sank to the ocean floor.
“The MOSS is broadcasting,” said Moody. The Polaris was now just drifting, its screw not turning, as silent as the big ship could be.
“I see it,” said the captain, tapping the screen in front of him. He looked at the narrowband profile that had suddenly appeared on his console, the 60 Hz tonal a bright line that was peeling away from them. He switched displays to see broadband sound, and watched the line tracing away from them that marked the “steam ring,” the signature of a very nearby submarine, the actual sound of high-pressure steam moving through pipes. It was a faithful duplication of their own noise being broadcast by the MOSS. “So that’s what we look like,” he said, almost to himself.
Moody came to his side. Despite her lack of faith in the plan to evade, she was excited, and determined, as always, to succeed. “Look!” she said excitedly, pointing at the display of the enemy boat. “They’re turning! They’re following the MOSS!”
“Make turns for three knots,” said the captain. “Let’s drive slowly away before they figure it out.”
Carlson allowed them to swing right to follow the sound, but the hair was standing up on the back of her neck. Something wasn’t right.
“Captain?”
Banach was standing beside her. Just as she had finely tuned instincts about enemy submarines, like any good XO, he had developed good instincts about his commander.
“I don’t know about this…” she said.
“Why? We can hear them clearly. If anything, it’s louder.”
“Exactly,” she said. “And faster. So why no noise from the reduction gear?”
He furrowed his brow at that.
“We’re following that sixty hertz because it’s all we’ve got.”
“Correct,” said Banach. “It’s all we’ve got. We haven’t always held both signals.”
“It’s going completely straight now, at a higher speed.”
“Maybe they’ve given up,” said Banach. “Perhaps they are abandoning their mission. Because of us.”
She snorted at that. “No,” she said. “You poor thing. It’s been so long since we’ve been in port, you’ve forgotten what it feels like to be seduced.” She swept through the sonar display, looking on all bearings for another sound, anything. But there was only silence, except for the 60 Hz beacon in front of them, the clearest they’d heard their target since they first acquired it.
Then, after forty-five minutes, it disappeared entirely.
“Shit!” said Carlson.
“I don’t understand,” said Banach, sweeping the cursor on the display through the ocean. “It just disappeared!”
“A drone of some kind,” said Carlson, already heading for the main plot. “We’ve been duped.”
She tapped her finger on a spot on the chart precisely between their current position and the spot where the fake Polaris had first turned and sped up. “Here!” she said. “Drive us here!”
“Left full rudder!” said Banach. The big ship turned to port.
“We’ve been driving away from them for almost forty minutes,” she said. “Assuming they are going very slow…”
“Maybe a mile or two?”
“If they were driving directly away from us,” she said.
“Have we lost them?” said Banach.
“We lost them,” she said. “They outsmarted us, fair and square.”
“We’re almost in position,” said Banach.