grating.

"Cassidy, you look in the cabins on the port side and I'll take those on the starboard," said the Lieutenant.

They separated, and Lawless proceeded along the starboard alleyway, glancing into each cabin to make sure that it was unoccupied. Everywhere there were signs of hurry and disorder, showing that the passengers had only had sufficient time to collect a few necessary articles before taking to the boats. All the starboard cabins proved to be empty, and, having reached the end of the alleyway, the Lieutenant crossed to the other side, where he expected to meet Cassidy. The latter was nowhere to be seen, however, and it was not till Lawless had made his presence known by a shout that he heard the mechanic's voice.

"Mr. Lawless, sorr, come quick! I've——"

The rest was drowned in a deafening crash, and the Lieutenant stepped back only just in time to escape being buried beneath tons of burning wreckage which had suddenly descended into the alleyway, followed by one of the huge iron girders that supported the deck above. He was thus cut off by a wall of blazing débris unless the starboard alleyway, through which he had just passed, was still open. Realising that there was not a moment to be lost, he dashed back, only to find his way barred by a portion of the engine-room bulkhead which had collapsed right across the passage.

Rushing back to the port alleyway, he was again stopped by the flaming barrier which lay across it. At first sight it seemed utterly impossible to get past it, but after a moment Lawless noticed a small, tunnel-like cavity beneath the wreckage where it was held up by the fallen girder, one end of which rested on the framework of the deck above. If he could only crawl through that and right underneath the smouldering furnace he might succeed in reaching the other side. So, dropping on all fours, he started to crawl into the opening, well aware that at any moment the girder might wholly collapse and crush him beneath its weight. If that happened he would be either mercifully killed outright or else pinned down and slowly roasted to death.

Almost suffocated by the smoke, he succeeded in forcing his way through and at last emerged safely on the other side. For a moment or two he was blinded by the smoke and could see nothing, but as he staggered to his feet a hand clutched his arm.

"Be the powers, 'tis yerself, sorr, the saints be praised!" cried the voice of Cassidy. "Are ye hurt, now?"

"No, no; but have you found anyone?"

"Shure I have that. There's a poor divil pinned down in his bunk yonder, and, though I've thried wid all me moight, I can't raise him."

"Then I'll lend you a hand, Mike. There's no time to lose, for this packet's settling fast," replied Lawless.

Cassidy led the way into one of the cabins, where a man lay in the lower berth, held down by the upper one, which had collapsed and fallen upon him. He was unconscious, evidently having been stunned by the falling mass. Between them they managed to remove enough of the wreckage to admit of his being dragged out of the berth. As they carried him from the cabin there came a thunderous crash, and Lawless saw the end of the great girder under which he had crawled give way and bring down with it the burning mass it had supported. Now, both fore and aft, they were imprisoned by a wall of flaming wreckage that made escape seem hopeless.

"'Tis the end av us, sorr," groaned Cassidy.

They laid their unconscious burden down in the alleyway, and while the mechanic set up a lugubrious wail Lawless started to rip up the matting with which the alleyway was covered.

"Here we are!" he exclaimed.

He pointed triumphantly to a circular iron plate let into the deck, and Cassidy, looking down after Lawless had removed this, beheld a dark cavity which emitted an odour of stagnant water.

"We can drop into the hold through there," said the Lieutenant, "and possibly we may reach the for'a'd deck. At any rate, it's our only chance. I'll go down first, and when you hear me shout lower that fellow down to me."

He gripped the end of the manhole, lowered himself through it, and then let go. There was a splash followed by a shout.

"Are ye all roight, sorr?" called Cassidy anxiously.

"Aye, aye, lower away," came the reply from the apparently bottomless depths.

Cassidy thereupon lowered the unconscious man through the hole, and held on till he felt the weight removed from his arms. Then he squeezed through the aperture, and, letting go, found himself nearly waist-deep in water and in almost utter darkness.

"The divil!" he exclaimed.

"Now you carry this man, and I'll lead the way," said Lawless, and Cassidy, catching hold of the limp body, slung it across his shoulder like a sack.

The Lieutenant slowly felt his way through the darkness towards the bows of the ship, guided only by the downward slope, for he could not see an inch in front of him. As they advanced the water became deeper, and he began to fear that it would cut off their retreat as effectively as had the fire.

"Damn!" he ejaculated abruptly. "It's all right," he added to Cassidy, who was close behind. "I bumped against an iron ladder. There must be a hatchway of some sort at the top; so you'd better wait here till I find it."

He ascended the ladder till he could go no farther, and then, after some trouble, managed to force open a small hatch. Climbing through, he found himself on the for'a'd well-deck and drew a deep breath of pure air which came as a life-giving tonic after the foul atmosphere from which he had emerged.

"Wait a moment," he shouted back. "I'll lower a rope for you to fasten round that chap's body. We can get him up quicker that way."

There was plenty of loose tackle strewn about the deck, and, selecting a piece, he made a running noose at the end and then lowered it through the hatch.

"All ready," came Cassidy's voice a moment later. "If ye'll just hold on for a minute, sorr, I'll come up and help haul."

In a few seconds the Irishman's head appeared above the hatch, and, stepping on to the deck, he helped Lawless haul the man up.

"Now fetch the machine for'a'd, Mike, while I try and bring this chap to his senses," said the Lieutenant.

Cassidy promptly climbed on to the taffrail and made his way amidships to the spot where the seaplane had been made fast. Meanwhile Lawless did his best to revive the unconscious man by splashing sea-water over him and trying artificial respiration. In a few moments the passenger uttered a faint moan and opened his eyes.

"Feeling better?" asked the Lieutenant cheerily.

The other stared at him with lack-lustre eyes and made no answer.

"You must try and get on your pins," said Lawless encouragingly. "Come on, now, I'll help you."

The man seemed to make a feeble attempt to use his limbs, and with a great effort Lawless managed to prop him against the taffrail. By this time Cassidy had brought up the seaplane, and together they succeeded in transferring their charge to it and placing him in the rear seat. This done, they cast off from the derelict and the Lieutenant started the engines. As he did so he gave a backward glance at the ship.

"She's going!" he cried, and as the seaplane started to rise there came a roar from behind, and the Nimrod, parting amidships, disappeared beneath the waves in a dense cloud of smoke and steam.

"That is the narrowest squeak I've ever had," he murmured.

He glanced at the petrol gauges, and saw that the tanks were nearly empty. There might be enough left to carry them another ten miles, but certainly not more. And, sure enough, in a few minutes the engines began to slow down, and there was nothing for it but to volplane to the surface. Their sole chance of rescue now lay in being picked up by some passing steamer, for, though the wireless apparatus could receive messages, there was no power to transmit them.

"Keep a bright look-out, Mike," said Lawless. "The