“The chief isn’t ready to concede that it was a planted explosion until his arson investigator can have a look,” Trevor said.
“Boats just don’t blow up, certainly not in that fashion,” Dirk replied.
“He asked if I had any suspicions, but I told him no.”
“You don’t think he can help?” Summer asked.
“Not yet. There’s just not enough evidence to be able to point fingers.”
“We all know someone from the sequestration plant is behind it.”
“Then we need to find out what the mystery is all about,” Trevor replied. He looked at Dirk and Summer steadfastly. “I know you’re short on time, but can you still oblige me with a search off Gil Island before you have to leave?”
“Our boat is loaded, and we’re more than ready,” Dirk replied. “Man the lines and we’ll be on our way.”
The ride down Douglas Channel was made in relative silence, with each wondering what sort of danger they had stumbled into. As they passed the sequestration facility, Dirk took note that the LNG tanker had departed the covered dock. He nudged the throttle to its stops, anxious to get on-site and see what lay beneath the waters off Gil Island.
They were nearly to the sound when Summer stood and pointed out the windshield. The black LNG tanker loomed up around the next bend, steaming slowly down the channel.
“Look how low she’s sitting,” Dirk said, noting that the tanker rode near her waterline.
“You were right, Summer,” Trevor said. “She was in fact taking on liquid CO2 at the plant. It doesn’t make any sense.”
The NUMA vessel charged past the tanker, quickly reaching the open strait. Dirk steered to the southern end of the strait, stopping the boat when he was even with the tip of Gil Island. He moved to the stern and lowered a sonar fish over the rail while Summer programmed a search grid into the navigation system. Within a few minutes they were under way again, moving back and forth across the strait, with the sonar fish tailing behind.
The sonar images revealed a steep and rocky bottom, which dropped from a fifty-foot depth near the shoreline to over two hundred feet in the center of the strait. Dirk had to play yo-yo with the sonar cable, raising and lowering the fish to match the changing depths.
Their first hour of searching revealed little of interest, simply a uniform sea bottom littered with rocks and an occasional sunken log. Trevor quickly grew bored watching the repetitive sonar image and turned his attention to the LNG tanker. The big ship had finally lumbered into the strait, cruising to the north of them at a snail’s pace. It eventually inched around the northern tip of Gil Island and disappeared from sight.
“I’d love to know where she’s headed,” Trevor said.
“When we get back to Seattle, I’ll see if our agency resources can find out,” Summer said.
“I’d hate to think she’s dumping that CO2 at sea.”
“I can’t imagine that would be the case,” she replied. “It would be too dangerous for the crew if the winds shifted.”
“I suppose you’re right. Still, something just doesn’t add up.”
They were interrupted by Dirk’s voice from the cabin.
“Got something.”
Summer and Trevor poked their heads in and gazed at the sonar monitor. The screen showed a thin spindly line on the seafloor that ran off to the side.
“Might be a pipe,” Dirk said. “Definitely appears man-made. We should pick up more on the next lane.”
They had to wait ten minutes, turning in front of the island and heading back into the strait on the next lane before they spotted it again. The thin line angled across the monitor, running in a northwesterly direction.
“Looks too big to be a communications line,” Summer said, studying the monitor.
“Hard to figure what would be out here,” Trevor remarked. “Outside of a few primitive hunting-and-fishing cabins, Gil Island is uninhabited.”
“Has to lead somewhere,” Dirk said. “As long as it’s not buried, we’ll be able to find out where.”
They continued sweeping through the grid, but rather than solve the underwater mystery they only added to it. A second line soon appeared, and then a third, all aligned in a converging angle to the north. Working their way through several more search lanes, they reached the conjunction. Like a giant seven-fingered hand lying on the bottom, the sonar revealed four additional lines that joined the others in a mass convergence. Piecing the images together, they could see that the lines all fanned out for approximately fifty yards, then ended abruptly. A single, heavier line extended north from the conjunction, running parallel to the shoreline. The sonar was able to track it for a short distance before it suddenly disappeared into the sediment close to shore. When they reached the end of the search grid, Dirk stopped the motor, then pulled in the sonar fish with Trevor’s assistance.
“It’s nearly seven,” Summer said. “We need to head back within the hour if we want to avoid running up the channel in the dark.”
“Plenty of time for a quick dive,” Dirk replied. “Might be our only chance.”
There was no argument from the others. Dirk slipped into a dry suit as Summer repositioned the boat over a marked spot where the seven lines had converged.
“Depth is ninety-five feet,” she said. “Be aware there is a large vessel on the radar headed our way, about fifteen miles to the north.” She turned to Trevor and asked, “I thought you said there’s no midweek cruise line traffic through here?”
Trevor gave her a confused look. “That has been my experience. They follow the schedules pretty tight. Must be a wayward freighter.”
Dirk poked his head in and eyed the radar screen. “I’ll have time for a good look before she gets too close.”
Summer turned the boat into the current while Trevor tossed an anchor off the bow and secured their position. Dirk adjusted his tank and weight belt, then stepped over the side.
He hit the water at nearly slack tide and was relieved to find the current minimal. Swimming toward the boat’s bow, he wrapped his fingers around the anchor line, then kicked to the bottom.
The cold green water gradually swallowed the surface light, forcing him to flick on a small headlamp strapped over his hood. A brown stony bottom dotted with urchins and starfish materialized out of the gloom, and he confirmed the depth at ninety-three feet as he adjusted his buoyancy. He let go of the anchor line and swam a wide circle around it until he found the object observed by the sonar.
It was a dark metal pipe that stretched across the seafloor, running beyond his field of vision. The pipe was about six inches in diameter, and Dirk could tell it had been placed on the bottom recently, as there was no growth or encrustation evident on its smooth surface. He kicked back to the anchor and dragged it over the pipe, resetting it in some adjacent rocks. He then followed the pipe down a gradual slope into deeper water until he found its open end twenty yards later. A small crater had been blasted into the seafloor around the opening, and Dirk noted a complete absence of marine life in the surrounding area.
He followed the pipe in the other direction, swimming into shallower water, until meeting the conjunction. It was actually three joints welded in tandem that fed six lines fanning to either side, plus one line out the end. A thicker, ten-inch pipe fed into the conjunction, trailing back toward Gil Island. Dirk followed the main pipe for several hundred feet until a ninety-degree joint sent it running north at a depth of thirty feet. Tracking it farther, he found it partially buried in a slit trench that had obscured its view from the sonar. He followed the pipe for several more minutes before deciding to give up the chase and turn back, his air supply starting to dwindle. He’d just reversed course when he suddenly detected a rumble under the surface. It was a deep sound, but in the water he could not tell which direction it came from. Following along the pipe, he noticed that sand started to fall away from its sides. He placed a gloved hand on the pipe and felt a strong vibration rattling down its length. With a sudden apprehension, he began kicking urgently toward the junction.