It was not easy going, for at every five or six yards a projecting ridge of rock had either to be skirted or surmounted--a task rendered doubly difficult by the darkness and the slippery state of the ground caused by the heavy downpour of rain. Presently Dick came to an abrupt halt and held up his hand. The single line of men stopped, some gripping their rifles in anticipation of an attack. The young officer found his progress barred by a small creek or gully that extended into a ravine, and evidently received a river or stream, for there was a considerable amount of water running towards the sea. It was imperative that this inlet should be crossed, but the Sub hesitated: not that he was loath to attempt to swim the stretch of intervening water, for already he was soaking owing to the dash through the surf. The nature of the opposite bank was the difficulty, for as far as he could make out in the darkness, the stream had worked the rocks smooth, and a ledge of stone quite five feet above the surface offered a wellnigh impassable barrier to a swimmer to draw himself clear of the water and surmount. "I'll see what it is like, sir," volunteered Trayner. "Maybe it's not so bad as it looks." The man lowered himself into the water and struck out. By dint of swimming obliquely upstream he contrived to gain the other side almost opposite the place where the others waited. Both up and down stream he swam for a considerable distance, till the Sub cautiously ordered him to return. "Felt like a mouse in half a bucket of water, sir," explained Trayner. "Sides are as smooth as a ship's sides--p'r'aps worse. I'll have another shot a little way up the creek." "You've done enough for the present, Trayner," said Dick, noticing the strained look about the man's eyes. "Two of you work away to the left and two to the right. Return as smartly as you can, and report." The men went off, leaving Dick and the main party literally to cool their heels by the side of the baffling gully. Presently the pair who had gone towards the opening of the creek returned with the information that there was a shallow bar where the stream joined the sea, and that it was easy to ford. Before they had finished their report the other two reappeared. "There's a way over about a couple of hundred yards up, sir," announced one. "There's a path on either side of this gully, and, what's more, the one on this side goes up towards the top of the cliff. Looks as If it's used a goodish bit, sir. If I might make so bold as to suggest, sir----" "Carry on, Webb." "There's a wholesome type o' craft lying alongside--wholesome as boats along these parts, sir. She's felucca-rigged. P'r'aps if we could cut her out----" "It's dead to windward, and as there's a bar at the entrance we couldn't get her across in heavy weather," objected Crosthwaite. "We'll push on, or we'll find the boats gone when we arrive at the rendezvous."