Some instinct made him look up, and his blue eyes widened in shocked disbelief. It was obvious what the Afrikaner’s next move had to be. The det cord was in front of his face, and one shot at close range from his pistol would blow them all to Hell!

With a cry of rage, Nash slammed the mattock down hard on the cable where it lay taut on the steel frame.

Boerman had just freed his pistol when the cable severed. Nash was staring into his eyes when the big man plunged. Fear, dismay and regret, perhaps for thwarted revenge, crossed his face in that split second. For one dreadful moment, it seemed the Afrikaner’s obscene luck would not desert him, for he fell neatly through the tightly packed log jam. But then, right on the waterline, he struck a partially submerged log with an awful thwack. Perhaps fate was determined to make sure of it, for a remnant branch punched up through his chest to transfix him like a vampire.

There was no time to organise a rope. Still clutching the mattock, Nash sprinted back around the sinkhole towards the cargo net winch, which offered the fastest route to the water.

Without hesitation, he launched over the edge. Plummeting thirty sickening metres through the log pile, he slammed into the water with a great stinging crack which numbed both feet. Regaining the surface, he swam through the chop, negotiating the additional hazard of shifting logs as the lower parts of the jam became buoyant.

Water was pouring over the edge of the access hole. Sliding over the jagged lip, Nash reversed position to drop into the churning pool below. In a couple of strokes, he crossed the inverted passageway, and climbed up to the floor hatch, which appeared as a darkened window. The infernal line of yellow det cord marked Boerman’s route to the torpedo room. Had he also found time to sabotage the forward bulkhead door on the lower deck?

Hauling himself inside the inverted floor hatch, Nash clung on to the horizontal ladder and lowered himself down. His feet didn’t quite reach the bulkhead, so he dropped the last half metre.

The bulkhead door was closed, but its circular handle was intact!

‘Mia!’ he bellowed, desperately hoping she was alive to hear him. ‘Hang on!’

Dropping to his knees, he tried shifting the handle. Boerman had opened this door and later closed it, but try as Nash might, it would not budge.

Nash tried loosening the friction by banging around the handle with the head of the mattock. There was no time to listen for an answering sound. At any moment, the water following the route he had just taken was going to pour in from above.