"Six o\'clock, sir, and a fine morning," announced Derek\'s batman, as he switched on the electric light, and handed the still half asleep officer a cup of strongly-brewed tea.

"By Jove! it\'s Christmas Eve, and I\'m Orderly Dog till eight o\'clock," thought Derek. "What with this wretched demobilization business and officers clearing out almost every day my turn comes once every five days. Well, here goes!"

Jumping out of bed Daventry dressed for the occasion, his garb consisting of a pair of flannel trousers drawn on over his pyjamas, a sweater, sea-boots, trench-coat, muffler, and cap—the last three items served to camouflage the rest for the work immediately in hand, that of being present on réveillé.

Making his way across the parade-ground the Orderly Officer entered the main building. Already the corridors were resounding to the shrill notes of the Orderly Sergeant\'s whistle and his strident shouts of "Show a leg, everybody!"

Derek had to visit personally twenty-five rooms and satisfy himself that their occupants were really awake. The sentries, too, had to be visited, and their early morning parade attended. These functions completed, Derek was at liberty to return to his quarters and attend to his toilet at his leisure, happy in the knowledge that his twenty-four-hour trick of "Orderly Dog" was nearing completion.

The spirit of Yule-tide was in the air. For days past officers and men had been going off on eleven days\' leave, while those who remained were entering into the prospect of a happy Christmas with the utmost zeal.

In the officers\' quarters the mess-room was transformed with brightly-coloured bunting, the walls being hung with flags, while the ceiling was almost hidden by chains and festoons of coloured paper. In the men\'s building each room entered into healthy rivalry with the others, and some of the decorations showed that a great amount of patience and artistic prowess had been employed to transform the usually Spartan-like quarters into bowers of evergreens.

Breakfast over and the eight-o\'clock parade dismissed, Derek was relieved of his duties as Orderly Officer, but he quickly found that, even during armistice-time and Christmas week, there is always something cropping up for an officer to tackle.

At six o\'clock the last liberty-boat had left, and the depot, sadly depleted, settled down to spend the eve of Christmas in strange surroundings. Derek was about to write some letters when a telephone message came through stating that a motor-boat had just arrived from Stourborough and asking what was to be done with her.

"Sticky sort of day for a half-decked boat to make a hundred-miles run," thought Derek, as he donned sea-boots and oilskins, for as senior officer on the station (there were only seven not on Christmas leave) he had to receive the new arrival and see that she was made secure for the night.

It was both blowing and raining. Pitch dark, too, except for the gleam of the Low Light. The tide was at half flood, and making strongly. Grinding against the pier was the motor-boat, manned by half a dozen hands in oilskins and sou\'westers.

"They won\'t be able to find moorings on a night like this, sir," remarked the Corporal in charge of the pier.

"And they look about done up," added Derek. "I\'ll find a fresh crew from the Duty Watch, and let them take her up to Fisherton Quay for the night. The old crew will come ashore and get a hot meal."

"We\'ve had nothing to eat since midday, sir," reported the coxswain of the boat. "She was making heavy weather of it coming down Channel, and we hadn\'t a chance to tackle any grub."

Having seen the well-nigh exhausted crew ashore Derek made his way to the mess-deck, where in response to the whistle and the order "Fall in the Duty Watch!" nine men paraded.

"I\'m calling for volunteers to take a boat up to Fisherton," said Derek. "The boat has been running continuously since daybreak, and the men are done up. I want a coxswain, an engineer, and two deck-hands. Those willing to carry on take one pace forward."

Without hesitation every man of the nine took a pace to the front, although for the most part they were new or only partially-trained hands. Selecting the new crew, Derek sent them off to don oilskins and sea-boots.

"I\'m not quite certain of the channel, sir," said the coxswain, as the crew mustered on the pier-head. "I\'ve only been up once, and that was in daylight."

"All right," replied Derek "I\'ll come with you." For nearly twenty minutes Derek waited on the boat in the driving scud and rain, for the motor, that had hitherto been running without a hitch, evinced no tendency to start.

"It\'s the rummiest Christmas Eve I\'ve ever spent," declared the young officer to himself. "Ah! well, it\'s all in a day\'s work. Nothing like yachting in December to give a fellow an appetite. By Jove! it\'s nearly dinner-time already, and this stunt will take an hour, if not more."

At length the engineer conquered the refractory motor, and, after running the engine with the clutch out for a couple of minutes, Derek decided to start.

"Cast off, there!" he shouted to the signalman. "Easy ahead!"

The boat gave a final grind against the pier, then forged ahead with a strong tide under her. Barely had she got beyond heaving distance of the pier-head, when, with a fierce roar, the whole of the confined space of the engine-room seemed to burst into flames. Simultaneously the motor ceased firing.

It was not an enviable situation. Adrift in a roughish sea with the engine-room well alight, it looked as if the crew had the choice either of being burnt or else compelled to take an involuntary bath in the icy-cold water. In the latter case there would be slight chance of reaching the shore, since the strong tide would carry the swimmers into the wide and exposed harbour, and in the pitch darkness of the night the p............