Summer adjusted the straps on her BC, which held a single dive tank, then clipped on a small dive bag containing several empty vials. She waited until Dirk had his tank on before slipping on a pair of fins.

“A midnight swim in the great Pacific Northwest,” she said, eyeing the stars overhead. “Almost sounds romantic.”

“ There is nothing romantic about a swim in forty-two-degree water,” Dirk replied, then clamped a snorkel between his teeth.

With a quiet nod, they both slipped over the side and into the chilly black water. Adjusting their buoyancy, they took their bearings and began kicking their way out of the cove and toward the facility. They swam near the surface, their heads just breaking the water like a pair of a prowling alligators. Conserving their dive tanks, they used snorkels to breathe, sucking in the brisk night air through their silicone breathing tubes.

The current was slightly stronger than Dirk had anticipated, led by the runoff from the Kitimat River at the head of the channel. They easily overpowered the head-waters, but the extra exertion built up body heat. Despite the frigid water, Dirk could feel himself sweating inside the thermal dry suit.

A half mile from the plant, Dirk felt Summer tap his shoulder and turned to see her pointing toward the shore. In the shadows of a jagged ridge of pine trees, he could make out a boat moored close to land. It was darkened like their own vessel, and, in the dim night light, he was unable to ascertain its dimensions.

Dirk nodded at Summer and swam deeper into the channel, putting a wide berth between them and the boat. They continued swimming at a measured pace until they closed within two hundred yards of the facility. Stopping to rest, Dirk tried to get a lay of the land beneath the blaring spotlights.

A large L-shaped building stretched across the grounds, its base next to the covered dock. The whine of pumps and generators emanated from the structure, which processed the liquid carbon dioxide. A separate windowed building adjacent to a helicopter pad stood a few yards away and appeared to contain offices. Dirk guessed that the housing accommodations for the workers were located up the road, in the direction of Kitimat. Off to his right, a sturdy pier jutted into the channel, hosting a single boat. It was the same dark speedboat that had chased them away earlier in the day.

Summer swam alongside, then reached down to her dive bag. Uncorking an empty vial, she collected a water sample while they drifted.

“I gathered two additional samples on the way in,” she whispered. “If we can collect another one or two around the dock, then we should have the bases covered.”

“Next stop,” he replied. “Let’s take it underwater from here.”