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 landed 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.