He had found what he was looking for and to stay any longer was to invite trouble. He turned and flutter-kicked towards the entrance. The light dimmed and he was aware of the current tugging at him.
He swam out into that strange, grey, phosphorescent world and paused to switch on the aquamobile. In that same moment it was torn from his grasp with a metallic clang and a shock-wave, spreading through the water, burst around him.
He turned and saw the frogman suspended in the water about twenty feet away, a weird sea-creature, full of menace, the moonlight glinting on his visor as he reloaded his spear-gun.
Mallory drove forward, pulling the heavy knife from its sheath. When he was perhaps ten feet away the gun ex-ploded again in a shower of silver bubbles. He swung desper-ately to one side. The spear hurtled past and he moved in fast, his knife cleaving through rubber and flesh.
The man’s body bucked agonisingly, blood rising in a dark cloud as Mallory pulled out the knife and snatched at the air-pipe. As it came free in his hand, air burst out at pressure, bubbles swirling past him on the way to the surface.
He could see the man’s face quite clearly now, eyes bulg-ing, teeth clamped together in agony. Quite suddenly he went over backwards in a graceful curve, like a leaf spiralling earthwards in autumn, the weight of his aqualung taking him down.
Mallory struck up towards the surface, chasing his aqua-mobile, which was rising slowly. He grabbed the handles and switched on, already aware of further shock-waves rippling through the water, bouncing from his body.
The aquamobile surged forward, helped by the turning tide. The sea-bed started to shelve again, and, below, he was aware of the pale forest of seaweed, the ribbons of black rock that were the beginnings of the reef.
Once again he was aware of a shock-wave curling around his body and he glanced to his right. Perhaps fifty yards away and coming up fast through moon-drenched water was a large underwater scooter, at least twice as long as his aqua-mobile, a frogman trailing behind.
Mallory kicked desperately, urging the aquamobile for-ward. And then the rocks swarmed up out of the gloom on either side and he rushed into the darkness of the Middle Passage. He switched on his spot, planing down to avoid the over-hanging roof. He was aware of a muffled throbbing in his ear and glanced back. A wide band of diffused light spreading through the mist told him that his pursuer wasn’t far behind.
He passed through a section where moonlight streamed in through cracks and fissures in the roof and knew that he was about half-way along the passage, somewhere above the wreck of the freighter. As he came into the clear section he plunged down and at ten fathoms a tapering steel mast loomed out of the gloom. Mallory held on with one hand and waited.
The darkness moved in on him with a terrible, suffocating pressure and the mast seemed to move a little as if the old freighter had rolled. He remembered the dark companionway, dead men’s bones crushed under a steel girder, and shivered, suddenly aware of the cold.
He could sense the turbulence in the water, waves rippling down. When he looked up there was the weird, incandescent glow of the spot-lamp on the other scooter as it passed over-head. He waited for a moment or two, then went up slowly.
At twenty feet he leveled out, switched on the motor, but not the spot, and went after the other scooter. Only in patches was visibility really bad and at this depth the moon-light streamed in through fissures in the rock like regularly spaced lamps along a dark road.
When he emerged at last from the great central nave into clear water he switched off the aquamobile and surfaced.
Raoul Guyon sat in the stern of the dinghy. A yard or two away the frogman stood waist-deep in water on the shelving reef beside his scooter, a loaded spear-gun in his hands. It was almost as if they were holding a conversation.
Mallory released his grip on the aquamobile, went under the surface and swam forward. He erupted in a surge of power, slid his right arm about the man’s neck and fell back-wards, towing him into deep water, tearing the air-hose from his mouth.