“Yes. See what the records show in the way of southern Madagascar shipwrecks in the past five years.”

“That I can do. Happy sowing.”

Dahlgren sealed the hatch and hoisted the submersible over the Alexandria’s stern. He waited until a radio call from the bridge confirmed they were at the designated drop spot, then lowered the sub. Once the grapple was freed, Dirk was given the okay to flood the ballast tanks, and the yellow submersible slipped under the waves.

The bottom appeared a few minutes later, and Dirk guided the submersible on its earlier northeast heading. This time they traveled less than fifty meters before crossing the familiar uplift.

“Kudos to Jack,” Summer said. “He played the currents almost perfectly.”

“Shall we drop the first sensor?” Dirk asked.

Summer checked their position, calculated from a dead reckoning program initiated at deployment. “Actually, we should move about thirty meters east to pick up our first track.”

Dirk made the adjustment. He eased the submersible to a flat section of seabed adjacent to the uplift and powered off the thrusters to settle the whirling clouds of sediment they had stirred up. Summer took over from there, activating a pair of articulated robotic arms. She clawed a vertical pit into the seafloor with one arm, then used the other to grasp a sensor from the basket. She wedged the sensor into the pit and covered up the main body of the sensor, leaving just the bright orange flag protruding from the seafloor.

“That went well,” Dirk said. He powered up the thrusters and shot down the rift at top speed.

“You in a hurry to get someplace?” Summer asked.

“I figured we might take another look at the wreck when we’re finished.”

Summer smiled. She’d had the same idea and made sure a backup video hard drive was aboard for them to film the wreck.

They proceeded along the fault, planting the remaining nine sensors along the seven-mile route. When the last sensor was secured, Dirk checked their position relative to the shipwreck. He maneuvered the submersible a short distance until the mass appeared before them. “Right where we left her.”

“I’ll get some video this time,” Summer said, activating the forward cameras.

Dirk ascended the submersible as they approached the hulk, heading immediately for the main deck. He crossed to the opposite rail, allowing Summer’s cameras to film the width of the ship’s beam and its open holds, which were missing their hatch covers. He was on a mission of identification, as he turned the submersible and its video cameras toward the high rear superstructure. Its design would offer another clue to the age of the ship and its builder.

Creeping up the front face of the superstructure, he zoomed over the bridge and hovered near the funnel, which protruded from the aft side. Commercial ships often carried the company colors or logo there, but this one was painted black.