He was pleased that his old ship had reached the rendezvous area eight hours earlier than expected. The water was too deep to drop anchor, so he ran the ship onto the outer edge of the ice pack before he ordered the engines shut down. Gillespie then notified Sandecker that his ship had arrived on station and was awaiting further orders.

The only reply was a succinct "Stand by to receive a passenger."

The respite gave everyone time to catch up on unfinished work. The scientists busied themselves analyzing and recording their findings into computers, while the crew went about making routine repairs to the ship.

They did not have long to wait.

On the morning of the fifth day since leaving the Weddell Sea, Gillespie was studying the sea ice through his binoculars when he saw a helicopter slowly emerge from an early-morning ice mist. It flew on a direct line toward the Polar Storm. He ordered his second officer to receive the aircraft at the landing pad on the stern of the ship.

The helicopter hovered for a few seconds, then descended onto the pad. A man carrying a briefcase and a small duffel bag jumped from an open cargo door and spoke to Gillespie's second officer. Then he turned and waved to the pilot who had flown him to the ship. The rotor blades increased their beat and the helicopter rose into the cold air and was heading for home when Pitt stepped onto the Polar Storm's bridge.

"Hello, Dan," he greeted the captain warmly. "Good to see you."

"Dirk! Where did you drop from?"

"I was flown from Punta Arenas on the Strait of Magellan by Air Force jet to the airstrip at the nearby Japanese research station. They were kind enough to give me a lift on their helicopter to the ship."

"What brings you to the Antarctic?"

"A little search project farther down the coast."

"I knew the admiral had something up his sleeve. He was damned secretive about it. He gave me no idea you were coming."

"He has his reasons." Pitt set his briefcase on the chart table, opened it, and handed Gillespie a paper with a set of coordinates. "This is our destination."

The captain looked at the coordinates and studied the appropriate nautical chart. "Stefansson Bay," he said quietly. "It's near, on the Kemp Coast not far from the Hobbs Islands. Nothing there of interest. It's as barren a piece of property as I've ever seen. What are we looking for?"

"A shipwreck."

"A wreck under the ice?"

"No," said Pitt with a half grin. "A wreck in the ice."

Stefansson Bay looked even more desolate and remote than Gillespie had described it, especially under a sky filled with clouds as dark as charcoal and a sea sullen with menacing ice. The wind bit like the needle teeth of an eel, and Pitt began to think of the physical effort required in crossing the ice pack to reach the continent's shore. Then the adrenaline began to pump as he thought of discovering a ship whose decks hadn't been trod since 1858.

Could it still be there, he wondered, just as Roxanna Mender and her husband had found it nearly a century and a half before? Or had it been eventually crushed by the ice or bulldozed out to sea where it finally sank deep in icy waters?

Pitt found Gillespie standing on a bridge wing, peering through binoculars at an unseen object far back in the spreading wake of the icebreaker. "Looking for whales?" he asked.

"U-boats," Gillespie answered, matter-of-factly.

Pitt thought the captain was joking. "Not many wolf packs in this part of the sea."

"Just one." Gillespie kept the glasses pressed against his eyes. "The U-2015. She's been following our wake ever since we almost collided with her ten days ago."

Pitt still wasn't sure he was hearing right. "Are you serious?"

Gillespie finally lowered the glasses. "I am." Then he proceeded to tell Pitt about the meeting with the U-boat. "I identified her from an old photo I have in my maritime library. There's no doubt in my mind. She's the U-2015, all right. Don't ask me how she survived all these years or why she's tracking this ship. I don't have the answers. All I know is that she's out there."

Pitt had worked with the captain on at least four projects over the years. He knew him as one of the most trusted captains in NUMA's fleet of research ships. Dan Gillespie was not a kook or someone who told tall tales. He was a sober and decisive man who had never had a black mark on his record. No accident or serious injury ever occurred when he trod the deck.

"Who would believe after all these years…" Pitt's voice trailed off. He was unsure of what to say.

"I don't have to read your mind to know you think I'm ready for a straitjacket," said Gillespie earnestly, "but I can prove it. Ms. Evie Tan, who is on board writing a story on the expedition for a national magazine, took photos of the sub when we nearly rammed her."

"Do you see any sign of her now?" Pitt inquired. "Periscope or snorkel?"

"She's playing coy and staying deep," Gillespie answered.

"Then how can you be sure she's out there?"

"One of our scientists dropped his underwater acoustic microphones over the side- he uses them to record whale talk. We trailed the listening gear a quarter of a mile behind the ship. I then shut down the engines and drifted. She's not a modern nuclear attack sub that can run silent through the depths. We picked up the beat of her engines as clear as a barking dog."

"Not a bad concept, but I would have trailed a weather balloon with a magnetometer hanging from it."

Gillespie laughed. "Not a bad concept, either. We thought about sidescan, but you'd have to get your sensor alongside for a good reading, and that seemed too tricky. I was hoping that now you've come on board we might find some answers."

A warning light went off in the back of Pitt's brain. He was beginning to wonder if he hadn't entered the twilight zone. To even consider a connection between the assassins from the Fourth Empire and an antique U-boat was plain crazy. And yet nothing in the whole incredible scheme made sense.

"Brief the admiral," ordered Pitt. "Tell him we may need some help."

"Should we harass him?" said Gillespie, referring to the sub. "Double back on our track and play cat and mouse?"

Pitt gave a slight negative shake of the head. "I'm afraid our ghost will have to wait. Finding the Madras takes first priority."

"Was that her name?"

Pitt nodded. "An East Indiaman lost in 1779."

"And you think she's locked in the ice somewhere along the shore," Gillespie said doubtfully.

"I'm hoping she's still there."

"What's on board that's so important to NUMA?"

"Answers to an ancient riddle."

Gillespie did not require a lengthy explanation. If that was all Pitt was going to tell him, he accepted it. His responsibility was to the ship and the people on board. He would follow an order from his bosses at NUMA without question, unless it ran counter to the safety of the Polar Storm.

"How far into the ice pack do you want me to run the ship?"

Pitt passed the captain a slip of paper. "I'd be grateful if you could place the Polar Storm on top of this position."

Gillespie studied the numbers for a moment. "It's been a while since I navigated by latitude and longitude, but I'll set you as close as I can."

"Compass headings, then loran, then Global Positioning. Next they'll invent a positioning instrument that tells you where the nearest roll of toilet paper is located and how many inches away."