"That's hardly the point. Our liberty is a small matter, but being made prisoners we should have no chance of letting our trawlers know that there is a masked battery being placed in position. No; I think the best thing we can do is to swim for it." "I'm game," declared Sefton. "It's quite possible that we'll pull it off all right," continued Dick. "You see there's a steady current always setting down the Dardanelles. That means that if we miss the nearest destroyer or trawler, we'll get swept across the bows of one farther down. Take off your gaiters and see that your bootlaces are ready to be undone easily. We won't discard any more of our gear till we're ready to plunge into the water. That's right; now follow me." Returning to the barrier at the entrance of the tunnel, the Sub wriggled cautiously over the obstruction until he could command a fairly extensive view of the gun emplacement and its surroundings. The rest of the artillerymen had not returned, while apparently the sentry, having been left to his own devices, had sought shelter from the rain and was enjoying a cigarette. Softly Dick dropped down, alighting on a pile of cut brushwood. He waited till Sefton had rejoined him, and the pair crept slowly and deliberately towards a gap left between the rock and the end of the semicircular rampart of sand-bags. Suddenly the Sub came to a dead stop almost within a handbreadth of the levelled bayonet of the Turkish sentry. CHAPTER V A Dash up The Narrows The Turk challenged. In the dim light he was not able to discern the uniform of the young officer. Perhaps he took him for one of the German taskmasters. At all events he merely held his rifle at the ready and made no attempt to fire. The slight delay gave Dick his chance. Dropping on one knee he gripped the sentry by his ankle, at the same time delivering a terrific left-hander that caught the fellow fairly in that portion of his body commonly known as "the wind". The Turk fell like a log. His rifle dropped from his nerveless grasp, fortunately without exploding. The back of his head came in violent contact with a lump of rock and rendered him insensible. "You've killed him," whispered Sefton. "Not much," replied Crosthwaite coolly. "He's got a skull as thick as a log of wood. At any rate we'll be spared the trouble of having to gag and truss him up. You might remove the bolt from his rifle and throw it away. It may save us a lot of bother if the fellow does pull himself together sooner than I expect." It was hazardous work descending the almost sheer cliff, for the spot where the officers had emerged was midway between the fort and the beach, and, being in a totally different part to the place where they had landed, they were unfamiliar with the locality.