Logan said, “She retrieved critical parts so NASA could determine what went wrong and make the shuttle safe to fly. She also salvaged a sunken F-14 and a missing Phoenix air-to-air missile we didn't want anyone getting their hands on. Some of the stuff involving the Russians is still classified.”

“What can you tell me about the mechanical arm?”

“The manipulator works like a human arm, with rotation at all the joints. The sub has two rubber wheels in the keel. It's not exactly a Harley-Davidson motorcycle, but it allows us to move along on the seabed. While the sub rests on the ocean floor, the arm can work a nine-foot radius.”

“Fascinating,” Pulaski said. “And its capacity?”

“It can lift objects up to two hundred pounds.”

“What about cutting tools?”

“Its jaws can cut rope or cable, but they can also hold a torch if the job is tough. As I said, very versatile.”

“Yes, evidently,” Pulaski said. He seemed pleased.

The sub had been moving in a classic search pattern, back and forth in a series of parallel lines, like mowing a lawn. The monitors showed the seafloor moving beneath the submarine. Vegetation was nonexistent.

Logan said, “We should be closing in on the location we spotted from above.” He gestured at a screen. “Hul-lo. Looks like the side scan picked up a hit.” He turned to the pilot. “Resume manual control and bring her down around twenty degrees to port.”

With gentle bursts of the thrusters, the NR-1 glided on a shallow angle. The battery of two dozen exterior lights illuminated the sea bottom with a sun-bright intensity. The pilot adjusted ballast tanks until the sub achieved neutral buoyancy.

“Hold steady,” Logan said. “We're coming into visual contact with our target.” He leaned forward and peered intently at the screen, his features bathed in the blue-green light. his the sub moved forward, bulbous shapes appeared on the screen, singly at first, then in groups.

“Those are concentrations of amphorae,” Pulaski said. The clay jars for wine or other liquid cargo were often found on ancient sunken ships.

“We've got the still and video cameras making a three-dimensional record for you to analyze later,” the captain said. “Is there anything you'd like to retrieve?”

“Yes, that would be wonderful. Can we bring up an amphora? Maybe from that pile.”

Logan ordered the pilot to put the sub on the bottom near a pile of clay jars. The four-hundred-ton vessel touched down like a feather and rolled forward. The captain called for the retrieval crew.