As they worked their way west, the coastal terrain flattened, revealing a mixed shoreline of coarse beaches and jagged boulders.

“Coming up on our third site,” Dirk said, comparing a satellite photo with the trawler’s navigation screen.

Summer held a pair of binoculars to her eyes, struggling to hold focus as the deck rolled. “Tell me when we’re directly offshore.”

Dirk plotted the boat’s progress. “Sometime now.”

Summer studied the shoreline, scanning a small gravel beach between two rocky outcroppings. She caught sight of a smooth shape, then was knocked against the bulkhead by a large wave. “Take us in closer.”

She searched for the object again—and spotted a smooth, rounded band tucked against the rocks.

“Something’s there, though it doesn’t look very big.” She passed the binoculars to her brother. “Take a look.”

“Yes, it’s some kind of man-made object.” He lowered the binoculars and looked at his sister. “Let’s go see what’s there.”

The captain had to sail another mile down the coast before he found a small cove that afforded protection from the waves. A small rubber boat was launched, and Dirk and Summer paddled the short distance to land. As they pulled the boat onto the beach, a squall blew in, dousing them with rain.

“Last time we were on an island,” Dirk said, “I would have killed for this kind of storm.”

They trudged up the coast in the downpour, fighting the stiff offshore breeze that pelted their faces with stinging drops. Despite the dismal conditions, Summer noted the rugged beauty of this island at the tip of South America. But the coastal terrain became monotonous in the pouring rain, and after a half hour of hiking, they became unsure about where they had spotted the anomaly.

Standing at the water’s edge studying the surrounding rocks, Summer finally spotted the object farther up the beach. It was a rusty curved plate of steel about six feet long, wedged firmly in the rocks.

“I’ll go out on a limb,” Dirk said. “It could be part of a submarine conning tower.”

Summer nodded and looked out to sea. “She probably struck those rocks and sank offshore. Or drifted out to sea again.”

“No,” Dirk said, his voice registering surprise. “I think that we’ve been looking in the wrong direction.” He tapped Summer’s arm and pointed inland. She saw only a narrow gravel beach. Beyond was a shrub-covered hollow at the base of a rocky knoll. The beach was barren, so she gazed at the hollow—and her jaw dropped.

Poking through the shrubs, another fifty feet inland, was the rest of the conning tower.

They scrambled across the beach and into the thicket, where the entire hull of a submarine was concealed in the brush. The vessel was three-quarters buried, but Dirk could tell they had approached it from the stern. Where there once was a drive propeller he saw only a mangled shaft. They hiked along the hull until they reached the exposed conning tower, which rose like an abandoned castle. Summer pulled a black-and-white photo from her pocket and compared it to the rusting steel hulk. It was a perfect match.

She smiled at her brother. “It’s the Barbarigo.”

They climbed up the battered remnants of the conning tower, where they could make out the imposing hulk of the entire boat through the underbrush.

“How could it have lan

ded way up here?” Summer asked.

“Probably a rogue wave. The area around Cape Horn is notorious for them. It must have been a real monster to throw her this far inland.”

Summer gazed at the bow. “Do you think her cargo is still aboard?”

It was the sixty-four-thousand-dollar question—and the reason they had rushed down to Tierra del Fuego. For Perlmutter had uncovered much more than just the sailor’s logbook. He had pieced together the mystery of the Barbarigo’s last voyage.

It all started with the German scientist Oswald Steiner, who had boarded the sub in Malaysia. Steiner, Perlmutter found, was a highly regarded physicist known for his research in advanced electromagnetics. Pressed into military research by the Nazis, he dabbled in their atomic program before focusing on a secret project of his own: a magnetic rail gun.

Steiner advanced the theory that a projectile launched at extreme velocities could travel up to fifty miles, allowing the Germans to bombard the southeast coast of England from Normandy. For the system to work, he needed the most powerful magnets in the world, and those came from one source. Rare earths.

In 1942 there was little demand for any of the rare earth elements, which were difficult to extract and refine. Germany and her conquests had few of the minerals, but Steiner found a lone source that could meet his needs. A small garnet mine in Malaysia, under Japanese control, extracted samarskite as a by-product. The samarskite contained high concentrations of the rare earth samarium, a key element in producing high-performance magnets.

Traveling to Malaysia, Steiner was stunned to discover a large stockpile of the mineral, amassed over years from mining operations. The local workers referred to it as Red Death due to its deep russet color, but it was Steiner who determined it was lightly radioactive, which in time had produced illness in some of the miners.

Thrilled with his discovery, Steiner requested transport of the samarskite back to Germany. An Italian submarine called the Tazzoli was assigned the task but was sunk in transit. When the Barbarigo arrived in Singapore, scheduled to pick up a supply of rubber and zinc, Steiner had her orders changed and stuffed her with samarskite. Accompanying the shipment home, he died with the Italian crew after they had to abandon the damaged sub.

Dirk looked down the Barbarigo’s forward deck at an exposed patch of steel near the bow. He descended the conning tower and hiked across the forward deck, which was covered with mud and rocks from the hill above. Summer followed him to an indented section near the bow. Kicking away the built-up soil, he exposed the rusted deck. He eventually uncovered a looped bar welded on horizontally. It was a handgrip for the forward hatch cover. Summer joined in scraping away the overburden until they cleared the cover, complete with its locking wheel latch.