Snugly hidden in the almost denuded compartment known as the captain's pantry, Alwyn Burgoyne and Jasper Minalto waited breathlessly for the impending explosion.

Discussing a hurried plan of action with Captain Blair—a quick change of programme necessitated by events over which they had no control—Burgoyne had acted promptly. Taking advantage of the confusion when the order had been given to abandon ship, the Third Officer and the faithful Minalto had climbed up the side and disappeared down the companion ladder without a single member of the pirate crew having the faintest suspicion of their presence. In the meantime the men in the life-boat, hurriedly coached by Captain Blair, had done their part of the business well.

A stout block had been bent to the heel of one of the davits. Through it was led a three-inch rope, one end being made fast to the life-boat's middle thwart close up to the knees, while the other was secured by means of a clove hitch to the crown of the davit. Unless looked for the rope would easily pass muster as one of the disordered falls of the davit. The idea was that, when the Donibristle sank, the strain on the rope would capsize and swamp the life-boat, pinning her hard and fast against the submerged side of the ship, and that was what exactly did happen.

The stowaways were confronted by two great and distinct perils. The pirates engaged in making up the explosive charges were not experts. They might easily err on the side of generosity when preparing the quantities, and when the explosion took place the whole ship might go up instead of down.

The second risk was that the Donibristle might sink in deeper water than the total height of her hull from keel-plates to the rail. In that case Burgoyne and Jasper Minalto would be trapped in a metal box and drowned without the ghost of a chance of saving themselves.

Yet unhesitatingly, though dubious of the result, they had taken the risk and were awaiting developments.

They could hear the plash of the oars as the boats pushed off, and the gentle grinding of the life-boat's gunwale as it rubbed against the rusty iron sides of the ship. Then came an ominous silence as Black Strogoff raised his hand and gave the signal.

The charges were fired.

Alwyn felt the floor-plates give as the whole fabric of the ship quivered under the internal impact. A waft of acrid fumes drifted into the enclosed space.

The two men exchanged glances as if to say, "Well; it's all right so far, but there's more to come."

The water was surging and hissing along the alley-way. The pantry-door, burst open by the outside pressure, was flung hard back against the bulkhead, and in an instant the two men were knee deep in water.

The level rose to their waists, and still there was no indication that the ship had settled on the bottom. The level was rising more slowly now. Without a jar the ship had touched the bed of the channel and was gradually sinking in the soft sand. Disappear she would eventually, but for the time being, perhaps for several hours, the subsidence was barely perceptible.

Then as the Donibristle listed slightly to port the level in the pantry fell a foot or eighteen inches, leaving the occupants standing nearly thigh deep in water.

Again they exchanged glances, but this time both men's faces wore a grin of satisfaction. They even chuckled softly, as they listened to the ravings of Black Strogoff and the carefully rehearsed lamentations and explanations of the boat's crew.

Half an hour later all was quiet without, save for the rattle of the rain upon the exposed portion of the deck. Black Strogoff, his assistants, and the working-parties had departed, their task accomplished; but there remained the unpromising prospect of their returning that afternoon to salve the sunken life-boat.

The downpour was a blessing in disguise. It enabled Burgoyne and his companion to talk without risk of being overheard by anyone on the cliff.

"Things'll be a bit more comfortable presently," said Minalto. "Tide'll be falling."

"Yes," agreed Alwyn. "It was half-ebb when they scuttled her. That means high-water about seven o'clock. Let's hope it will be a dark night and not too much wind. You say you know where the two buckets are stowed?"

Minalto made no reply. He was staring thoughtfully at a corner of the pantry.

"Anything wrong?" inquired Burgoyne. "You haven't got cramp, I hope?"

"No, sir," replied the man. "It's a mort too warm to give I cramp. I'm just a-thinkin', sir. See that li'l boiler? Couldn't us get 'en away an' use 'en for a water-tank?"

Burgoyne jumped at the idea. The "li'l boiler" was in reality a galvanized iron bin used for storing flour, and would hold about fifty gallons of water without much chance of its contents spilling over the top, as it was fitted with a metal lid.

"You're a gem of the first water, Jasper!" exclaimed Burgoyne enthusiastically. "Come on, let's get it adrift at once. It will be something to do."

By the aid of broken-off ends of files it was a fairly simple matter to unscrew the brass clamps. Examination of the tank showed that it was half filled with mouldy flour.

"Soon clean 'en," declared Minalto. "Then when us gets round t'other side fill 'en wi' water, and put 'en aboard the boat again."

"Hardly," demurred Burgoyne. "That tank even if only filled to within two inches of the top would weigh well over four hundredweights. No, we'll have to leave it in the life-boat and fill it up by means of the buckets. By Jove! that knocks Angus and his canvas tanks into a cocked hat. We'll clean it out now. Salt water won't hurt if we wash it with fresh later on."

The hours dragged wearily on. Both men were hungry and thirsty, for they had come unprepared for the task on which they were at present engaged. But at length the darkening gloom in the alley-way announced that night had drawn in, and the time for strenuous activity was at hand.

Glad to escape from their cramped quarters, for the rising tide was beginning to make things far more uncomfortable than before, the two men emerged from the pantry, dragging their prize after them.

It was now quite dark. The rain had ceased, but the sky was overcast. A north-easterly breeze was ruffling the waters of the lagoon. Shorewards there was nothing to denote human occupation. The cliffs of the secret base rose gaunt and forbidding against the faint loom of the sky, with no indication to show the hive of piratical industry that flourished within the limits of those unscaleable precipices.

Very cautiously Burgoyne and his companion crept towards the davit to which had been made fast the rope pinning down the life-boat. The manila had shrunk in the wet to such an extent that the clove hitch had jammed. It was only by using the broken file as a marline spike that Alwyn succeeded in teasing out the tenacious hitch.

The result though expected was nevertheless startling. The whaler, under the buoyancy imparted by six large air-tight copper tanks, bobbed up like a cork, making a splash that might be heard on board the Malfilio and even by the pirates on shore.

"They'm thinkin' it'll be a girt shark," commented Minalto, as he slipped over the side with a bucket to bale the boat.

Burgoyne joined him, and in twenty minutes the bottom boards were figuratively "dry". The exercise also helped to restore the circulation............