The Prusalka still listed at an angle as Dmitry scrambled to his feet and pulled himself back into his seat. He wiped his face, and took the wheel again. “Check for fires.”

Mironov felt his temple and his hand came away wet and red. He looked towards the front and saw something that scared him more than the leviathan outside – there was now a thin line running down the center of the curved glass window.

He blinked and pointed. Dmitry seeing him, snapped his head around, and also saw the hairline crack. He leapt forward to reach up and lay fingers on it.

“Impossible,” he hissed.

The next impact jolted them again, and Dmitry’s voice was high and shrill as he scrabbled backwards along the floor. The submersible was being pushed backwards, but what had frightened the Russian pilot was what covered the impossibly strong viewing glass. The Megalodon had them in its mouth, lips pulled back exposing the hyper-extended jaws, and huge triangular-shaped teeth. And behind them, a cavernous void of internal ribbing and ventral flaps, down a train-tunnel sized gullet.

Mironov rose to his feet. Statistics ran through his head: the jaws of an average Great White Shark can exert a bite pressure of up to one-point-eight tons, but this thing with its pure mass would be able to exceed that by at least a dozen times. He remembered what Yegor had told them about the Prusalka’s ability to withstand crush depth pressure – no problem, as long as it was exerted al over the craft at once. He suddenly wished Jack Monroe were here so he could ask the expert’s advice.

There was a smell of smoke in the cabin, and the engines droned on, but were useless as something much bigger and more powerful was now in control of their fate. The submersible’s angle changed – downward – Mironov began to slide.

Dmitry wrestled with the wheel. “It’s trying to take us down.” He grimaced and then yelled over his shoulder. “I’m going to deploy electric charge.” He flicked up the clear cover over the array of switches which he set on, and then calibrated a dial. “Priming for full charge this time.” He didn’t bother to count, but instead hammered down on the large flat button. The cabin lights flickered but unlike with the squid, the Megalodon either didn’t feel it, or didn’t care.

Dmitry kept his hand down hard on the button until the internal lights dimmed and the smell of smoke now pervaded the cabin. The submersible suddenly kicked backwards in the water, but began to list to starboard.

“We’re free.” Dmitry spun, grinning madly.

“Free, but dead in the water,” Mironov observed as he sat slowly.

Dmitry tried the controls but nothing responded. The red internal lighting was down to a few ruby jewels along the cabin ceiling, and only some of the screens still shone.