Ken felt a dull stupor creeping over him, a curious sense of unreality. His thoughts began to wander. So much so that at first he hardly noticed the curious sucking splash which came from the water some little distance to the left.

It was Roy who called his attention to it.

'Ken, there's a thundering great fish out there. Do they keep sharks in these waters?'

Before Ken could reply, the splash was followed by a slight grating sound, then a dull clank, like two metal plates being lightly struck together.

Hope dawned suddenly in Ken's heart, sending a tingling shock through the whole of his perishing body.

'That's no fish,' he muttered. 'That's no fish.' Then raising himself as high as he could out of the water he sent a sharp cry for help pealing through the darkness.

'Hallo! Hallo! Who's that?'

Never had Ken been happier to hear the sound of a human voice.

'Three survivors from the "Maid of Sker,"' he answered. 'Our boat's upset.'

'Hang on!' came the quick reply. 'We'll have you out in a jiffy.'

There came low voiced orders, the low purr of an engine, and a low dark bulk topped by a curious square-looking turret came gliding towards them.

'What is it?' muttered Roy in a dazed tone.

'A submarine,' Ken answered gladly. 'That's her conning tower. Here she comes. Hang on to Gill, or the wash will take him off.'

A moment later, and the long gray craft swam up right alongside of the dinghy. It was the most beautiful bit of steering imaginable. A hand reached out and pulled the dinghy close against the hull, and strong arms gripped and lifted the three aboard.

Ken felt himself swung gently up the conning tower, then he was lowered with equal ease and skill through the open hatch. Within an incredibly short time he was flat on a mattress laid on the throbbing steel floor of the submarine.

A keen-faced officer stood beside him.

'Both the sweepers gone?' he asked gravely.

'I'm afraid so, sir. The "Swan" was knocked all to bits, and we saw the "Maid" sink. I believe we are the only survivors.'

'We heard the firing, but couldn't get here sooner. But you're in khaki. How's that?'

'Horan and I are escaped prisoners, sir. We stole a boat up by Kilid Bahr, and were picked up by the "Maid." Gill is the only man left from the trawler. He was one of the crew of the "Maid's" dinghy that went to help the "Swan's" people.'

'And you?'

'Horan and I were trying to save him when the "Maid" was hit.'

The other nodded approvingly.

'Ah, you're Australians. Good men! But I see you're about all in. I shan't bother you with any more questions now. Williams, see these men have a change, and a tot of rum. And some of you give 'em a good rub down. They're stiff with cold.'

He nodded again and went off.

Williams, a burly torpedo coxswain, at once took charge of Ken. His big hands were as tender as a woman's as he stripped off the boy's soaking clothes and substituted for them a fresh suit of warm lammies. Before putting them on, he gave Ken such a rubbing with a rough towel as sent the stagnant blood tingling through every vein.

'Thanks awfully,' said Ken gratefully. 'I say, how's Gill? He got knocked silly with the blast of the shell that sunk the "Swan." Is he hurt?'

'He ain't hit, anyway,' said Williams. 'He's swallowed a bit more salt water than suits his innards, but he'll pull round all right, never you fear.

'Here, drink this down,' he continued, handing Ken a thick mug full of some steaming mixture. Ken swallowed it obediently. It was thick Navy cocoa, laced with a dash of rum.

It sent a grateful warmth through every inch of Ken's body, but its immediate effect was to make him so drowsy that his eyes began to close.

'That's all right,' he heard Williams remark in a satisfied voice. 'Forty winks won't do you no manner of harm.' The last thing Ken remembered was being wrapped in a blanket. Then he dropped back on the mattress and almost before his head reached it was sound asleep.

He woke to the purr of engines and a warm thick atmosphere smelling strongly of oil and illuminated by white electric lamps. For the moment he could not imagine where he was nor what had happened. It was not until he rolled over and saw Roy lying stretched on another mattress beside him, and Gill a little beyond, that any sort of recollection came back to him.

He stretched himself. He was sore all over, but otherwise fit enough and very hungry. Then he sat up.

A burly figure came towards him, walking with that curiously light-footed tread which becomes second habit in a submarine. It was Williams, the coxswain.

'Well, young fellow me lad,' he remarked genially, 'how goes it?'

'Top hole, thanks. A bit empty. That's all.'

'If that's your only trouble, we'll soon fix it. Can you walk?'

'You bet.'

'Then come along forrard, and we'll see what cooky can do for you.'

Cooky's efforts consisted in biscuit, butter, sardines, jam, and lashings of hot strong tea, to all of which Ken did the fullest justice.

'And how d'ye like life under the ocean wave?' asked Williams, who was watching Ken's progress with the eye of a connoisseur.

'First time I ever tried it,' said Ken, glancing round the long, narrow interior which seemed merely a packing case for a maze of intricate machinery. 'What is she? What class I mean?'

'She's G 2, sonny, and don't you forget it. The last word in submarine gadgets. Twenty knots on the surface, and twelve submerged. Carries eight o' the biggest and best torpedoes, any one o' which is warranted to knock the stuffing out o' the "Goeben" or any other o' Weeping Willy's super-skulkers.'

'Where are we now?' inquired Ken with interest.

'Couldn't say precisely. But somewheres about ten fathom below the shinin' surface of the Dardanelles.'

Ken felt a queer thrill. There was something uncanny in the thought that they were spinning along, sixty feet below the sea-level, cut off from all the living world.

'Pass the word the commander wishes to see Carrington,' came a voice.

'Lootenant Strang wants you,' said Williams. 'Go right aft. Sentry'll show you. And go careful, mind you. Submarines ain't the sort o' shops for foot races.'

Ken went cautiously back past the amazing tangle of spinning, whirling machinery. Where the long interior narrowed to the stern hung a thick curtain. The sentry silently parted it, and Ken found himself in the officer's quarters of G2. They were as plain as the steerage on a liner. Just two bunks and in the middle a table at which Lieutenant Strang sat, busily writing.

He glanced up as Ken entered, and, saluting, stood to attention. Ken noticed, with inward approval, the strength and intelligence in the clean-cut features of the commanding officer.

'Feeling better, Carrington?'

'Quite all right, sir, thank you.'

'Had breakfast?'

'Yes, sir.'

'I want to hear what you've been doing. Let's have the whole yarn.'

Ken told him. He put it as shortly as he could, but gave his story clearly and well. Lieutenant Strang listened with the deepest attention.

''Pon my word, you and your chum have been going it some!' he remarked when Ken at last finished. 'So you're a son of Captain Carrington? How is it you did not take a commission?'

'I didn't think I had any right to it, sir,' Ken answered simply. 'It seemed to me it was the sort of thing one ought to win.'

'Just so. I dare say you are right. I hope you'll get one anyhow. But see here, I can't put you ashore. We're going north, not south.'

'Going up through the Straits, sir?' exclaimed Ken. 'We've gone. We're opposite Bulair this minute, so far as I can judge.'