“No, but I bet Audry is. What kind of mileage does she get on a tank of battery acid?”

“The batteries for high-speed operation are only designed to last eight hours. We never run her past seven hours, though, to make sure she has enough juice to propel herself from deep water to the surface. She's been in the water now about six hours,” Summer said, glancing at her watch, “so we'll need to call her back for a battery change within the next hour.”

A pop-up window suddenly appeared on the computer screen, signaling receipt of the latest data upload.

“Only one more file to go till we've covered the first search box,” remarked, standing up from his computer console chair and stretching his arms. “I better identify the boundaries of the next search grid. Can you take a look at the next data feed?”

“Sure, I'll just go ahead and find it for you,” Summer joked as she took his seat and typed a string of commands into the keyboard. A new set of images appeared on the screen, a five-hundred-meter swath of ocean bottom scrolling from top to bottom, which resembled the aerial view of a hard-packed dirt road through the desert. Summer had adjusted the color images in a golden hue so that the occasional rock or mound on the bottom cast a brown-tinted shadow. She studied the monitor closely, watching the same monotonous sea bottom glide by. Suddenly, a dark smudge appeared on the top right side of the screen and grew larger as the readings rolled down. The smudge was a shadow, she quickly realized, created by a long tubular shape that was crisply defined in a dark shade of russet.

“My word, there it is!” she squealed, surprised at her own voice.

A small crowd gathered around Summer as she replayed the image at a slow speed several times. The distinct outline of a submarine was clearly evident, complete with an upright conning tower that cast a long shadow to one side. The image roughened near one end of the vessel, but Summer measured the object at well over three hundred feet.

“Sure looks like a submarine, and a big one,” she said, not sure whether to trust her eyes.

“That's our baby,” Dirk said confidently. “Looks just like the image we scanned of the I-403.”

“Nice work, Summer,” Morgan offered as he approached the commotion.

“Thanks, Captain, but Audry did all the work. We better pull her aboard before she makes her way to China.”

Summer typed in a new handful of commands and a signal was relayed from the transducers to the underwater vehicle. In a matter or seconds, Audry terminated the search pattern and propelled herself upward, where she broke the water's surface a quarter mile away from the Sea Rover. Summer, Dirk, and Morgan watched as a retrieval team in a rubber Zodiac scooted over to the idling yellow sensor and clamped it to the gunwale. The team slowly made their way back alongside the research ship, where Audry was hoisted out of the water and replaced in her cradle on the stern deck.

As the second of the two transducers was hoisted back aboard, Dirk admired a large exploration vessel that was inching past them a mile away, a Japanese flag wafting off its high bow platform.

“Cable-laying ship,” Morgan said, catching Dirk's gaze. “She followed us out of the Inland Sea.”

“She's a beauty. Doesn't appear to be in any hurry,” Dirk said, noting the vessel's slow speed.

“Must be operating under a daily billing rate contract,” Morgan laughed, then turned his attention to ensuring the transducers were securely aboard.

“Maybe,” Dirk replied, smiling, but a vague caution tugged at the recesses of his mind. He shook off the feeling and refocused his thoughts on the task at hand. It was time to take a look. at the I-411 up close and personal.

The crew of the Sea Rover wasted no time in making preparations to investigate the submerged target. Captain Morgan brought the ship around and positioned it directly above the target, using the GPS coordinates identified by Audry. Computerized side thrusters on the research vessel were activated and the Sea Rover was parked in place, constantly self-adjusting its position against the wind and current with the thrusters to remain fixed within a few inches of the designated mark.

On the aft deck, Dirk, Summer, and First Officer Ryan carefully walked through a pre dive checklist for the Starfish. Specifically designed for deep-water scientific exploration, the Starfish was a high-tech submersible capable of operating in depths up to two thousand meters. Resembling a giant translucent ball on a forklift, the Starfish cat-tied two operators in a six-inch-thick reinforced acrylic bubble that offered a panoramic view of the sea. Wedged into a bright orange supporting buttress, the see-through sphere was filled with a myriad of sensors, still and video cameras, and coring devices. Four sets of adjustable thrusters were mounted behind and beneath the bubble, which provided the sub with a high degree of maneuverability. Adding to the functionality were a pair of steel articulating arms mounted on either side of the bubble, which could be used for collecting samples and manipulating the multiple data analysis devices. Since the right mechanical arm was larger in size than the left, the whole submersible took on a crablike appearance when operating on the seafloor.

“I think we're set,” Summer said, eyeing the last item on her clipboard. “You ready to get wet?”

“Only if I get to drive,” Dirk grinned back.

Clad in aqua-colored NUMA jumpsuits, the two siblings threaded their way into the tiny chamber through a hatch in the rear. Though cramped inside, Dirk and Summer sat comfortably in a pair of padded captain's chairs, which faced out the front of the acrylic bubble. Dirk slipped on a communications headset and spoke to First Officer Ryan.

“This is Starfish,” he said, checking the system. “Ready when you are, Tim.”

“Prepare for deployment,” Ryan's voice rang back.

An overhead boom reeled up a thick cable attached to the submersible by a pair of eyelets, raising the underwater vessel straight into the air and suspending her three feet above the deck. As the Starfish hung floating in the air, Ryan pushed a button on a side console and the deck suddenly split open beneath the submersible, sliding on rollers to either side of the deck. Exposed beneath the dangling submersible was the pale green water of the East China Sea. Ryan hit another switch and a circular band of underwater floodlights burst on, outlining the perimeter of the large moon pool cut into the Sea Rover's rear hull section. A large meandering grouper was caught illuminated Dy the sudden flash of light and quickly bolted from beneath the odd hole in the ship's hull. The orange submersible was slowly dropped through the hole and into the water, the lifting cable released after Dirk confirmed that all systems were operational aboard the Starfish.

“Cable is released,” Ryan's voice announced over Dirk's headset. “You are free to swim. Happy hunting, guys.”

“Thanks for the drop,” Dirk answered. “I'll honk the horn when we get back from the store.”

Dirk tested the thrusters one last time as Summer opened a ballast tank, allowing a flood of salt water to fill the chamber. Negative buoyancy was quickly achieved and the submersible began slowly dropping into the depths.

The pale green water gradually dissolved to brown, then faded to an inky black as the Starfish sank deeper. Summer flicked on a switch and a powerful bank of xenon arc lights illuminated their path, though there was little to see in the murky water. Dependent on gravity to reach the bottom, it took about fifteen minutes to make the nearly thousand-foot descent to the seafloor. Despite the frigid water temperatures outside, the occupants soon became warm from the electronic equipment churning about them in the insulated acrylic and Summer finally turned on an air-conditioning unit to keep themselves cool. Attempting to make the time go faster, Dirk rehashed a few of Jack Dahlgren's stale jokes while Summer brought her brother up to date on the sea pollutant survey taken off Japan's eastern coast.