"We'll leave the door unlocked," declared the sub. "He's not likely to give trouble, and we can't be accused of leaving a prisoner to drown in a boxed-in cabin—like the Huns have an unpleasant habit of doing. Hullo what's that?"
The two men for'ard were shouting an pointing aft. In spite of the roar of the engine, Farrar understood. They were afraid of being caught in the suction of the rapidly revolving propellers.
"Quite a reasonable fear," muttered the sub. "I've felt the same sort of thing myself; but I'm sorry I can't stop to let them dive in gracefully. I'll slow down a bit, although it's jolly risky for us."
By means of the reverse gear lever in the cockpit—a supplementary device to enable the motor to be regulated in the event of the mechanism being incapacitated—Farrar threw the propeller' shafts out of clutch. The boat began to lose way appreciably.
"Beeilen Sie sich!" shouted the sub.
The two Austrians required no second bidding. Both leapt feet foremost into the water, striking out with the utmost vigour, as if afraid that their late captors would restart the propellers and "do them in."
The patrol boat quickly worked up to her previous speed, but the pursuing craft had decreased the intervening distance to about a mile. Already the first gleam of dawn was stealing across the eastern sky, silhouetting the dark outlines of the destroyer against the grey blend of sea and air in the distant horizon.
"Good business!" exclaimed Farrar. "She's reversing engines to pick those fellows up."
The Austrian skipper was no novice at the job, nor was he a man to waste time in stopping to pick two seamen out of the water when there were greater issues at stake, Merely stopping the engines he steered the still swiftly moving craft close to the swimmers; bowlines were thrown them, and in a very brief space of time they were both hauled on board.
Yet during this manoeuvre the destroyer lost more than the patrol boat had done when Farrar humanely declutched the propellers. The distance between pursuer and pursued had increased to nearly two miles.