Grasping the lowermost rung of the ladder leading to the conning-tower, Tregarthen tried to collect his scattered wits in order to find some explanation for the sudden tilting of the helpless boat. Perchance her afterpart had rested over a fissure, and the slimy bed had given way as the hull began to settle down.
Then the sensation of drowsiness began to reassert itself, and the lieutenant felt his grip relaxing, till, just as he was on the point of joining his companions who lay in a confused heap—dead perhaps, but at all events unconscious—a voice exclaimed peremptorily, "Empty your ballast tanks."
It was through the receiver of the loud-speaking wireless telephone that the voice came. It meant that the submarine had been raised several fathoms, sufficiently for the telephone to be used once more.
Staggering up the sloping deck, Gerald grasped the pump lever of the 'midship tank. Thank goodness the pressure had been reduced sufficiently for the powerful pump to act.
With his last remaining strength Tregarthen plied the lever, till at length a ruddy sunset glare streamed in through the thick glass apertures in the conning-tower. The submarine was awash.
Climbing the ladder into the conning-tower Gerald threw back the double-action lock securing the hatchway, but the task of opening the massive steel plate was beyond him. The next moment he was drinking in the pure air, supported by a burly petty-officer who had slid down from the cruiser to the deck of the submarine.
"Hurry up and pass these men out," he heard Captain Brookes exclaim. "Perhaps some of them may be still alive."
Half conscious, Gerald was lifted over the side of the Olive Branch, Jack Stockton supporting him with the utmost solicitude.
"A pretty fine pass," he heard Captain Brookes remark. "I did not think that Palmer would disobey orders. And nothing gained, after all."
Gerald stopped, just as he was about to be assisted down the companion ladder, and with a sudden impulse that surprised his chum, he wrenched himself clear and staggered across to where the captain stood.