Gerald feared for the success of their search in that maze of trackless ooze, for without a mark from which they might take their bearings the submarine must eventually wander far from the spot where she had descended. He glanced at his watch, it showed a quarter to five. That meant that in another twenty-five minutes the submarine must reach the surface, or Captain Brookes would imagine that some disaster had befallen them. "How's the air below there?" sang out the officer in charge. "All serene, sir; the mice are quite chirpy," replied one of the seamen. "You had better be on the safe side and release a little more oxygen," continued Palmer. "Then stand by with the grapnel." The grapnel was secured to the outside of the submarine, whence by means of an electric wire it could be lowered and engaged with the object to be salved. Its length was not sufficient to allow the possibility of fouling either the planes or the propeller. "All ready, sir." At that moment Gerald's quick eye caught sight of a mass of twisted aluminium bars and canvas. It was the monoplane. Wedged between the framework was a long, thin object covered with a greyish material. The two officers could hardly recognise the body of the treacherous and ill-starred aviator. Overcoming their feelings of horror the two men looked for the missing reciprocators. The submarine was now brought to a standstill, her keel resting on the ooze, while her searchlight played straight upon the victim of the tragedy. "There they are, I believe; do you see those bulges under his coat?" exclaimed Palmer. "It certainly seems so," replied Gerald. "Now, what do you propose to do?" "Rise right over the aeroplane, engage the grapnel, and blow the ballast tank." "Mind you don't overrun it, and get the propeller fouled," continued Tregarthen. "I'll try not to. Now, here goes." Slowly the submarine began to rise; the grapnel was dropped, and with an almost imperceptible jar the implement became entangled in the wreck of the monoplane. "Easy ahead." The motors, running jerkily in their endeavour to overcome the pressure of water on the propeller-blades, were gradually advanced to their utmost capacity, but still the submarine remained anchored to the bottom of the sea, till with a succession of sharp jerks the little craft wallowed helplessly in the ooze. "Blow the for'ard ballast tank," ordered Palmer, calmly. "She'll rise like a bird." Two of the men hastened to pump out the tank, but so great was the outside pressure that they were unable to expel the water. On the contrary, a slender stream hissed through the glands of the pumps with terrific force. One of the seamen, struck full in the face by the jet of water, was hurled against the arched sides of the vessel. "Belay there!" exclaimed the commander, seeing that more harm than good was likely to result; then turning to Gerald he whispered, "Now, what's to be done?"