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.

“Think it’ll budge?” Summer asked.

Dirk gave the wheel latch a few firm kicks to break the seal. “Give me a hand and we’ll find out.”

They both gripped the wheel and threw their weight against it. After several tries, the latch broke its decades-long grip and spun freely. Dirk gave his sister a hopeful wink and heaved open the hatch.