“The lower hatch is sealed tight, Doctor,” Hayes said, his voice deep and steady despite the roar of the water.

“The pneumatic locks are engaged from the inside, but the crew isn’t responding to the intercom.”

“They’re trapped in the forward torpedo room,” I said, wiping salt water from my eyes.

“Turner locked the system. He’s venting the main ballast tanks to flood the hull.”

Hayes looked toward the pier, where Carter was now backing away into the shadows of the warehouse.

“That coward has the manual override keys,” Hayes growled.

“We don’t need them,” I said, grabbing the lapel of his wet jacket.

“The keys only work on the standard valves. Turner blocked those through the main computer grid.”

“Then how do we stop the flooding?” Hayes asked.

The submarine shivered beneath us, a low, metallic vibration that rattled my teeth.

The bow was beginning to pitch downward into the black river.

A burst of white foam erupted from the forward escape trunk, indicating the air was being pushed out by the incoming water.

“There is a secondary system,” I said, leaning close to his ear to be heard over the noise.