At the conclusion of the pirate lieutenant's speech silence fell upon the close ranks of the prisoners. Porfirio conferred with his subordinates for some moments, then, turning abruptly, walked down to the Malfilio's boat. Henriques accompanied him; but Strogoff, who had been told off to remain as a sort of deputy-governor of the island, stood in the centre of the hollow square, his dark eyes closely scrutinizing the faces of his captives.

Presently he shouted:

"Place all the luggage on the ground."

The "luggage" for the most part consisted of handkerchiefs containing the men's scanty and hurriedly-collected kit. Two or three of the officers had brought small handbags, while the purser had taken the precaution of landing a portable medicine-chest.

"You have been searched for arms?" inquired the pirate lieutenant, addressing Branscombe, and without waiting for that worthy's reply he continued: "Goot; we will now the luggage search."

It was not a lengthy business. One of the guards undertook the examination of the kit, while Strogoff watched the proceedings. Since there was little of value, nothing was taken with the exception of shaving- and looking-glasses, razors, and scissors.

The prisoners, preceded and followed by armed guards, were then marched off. For a hundred yards or so they kept to the sandy beach until they arrived at a cleft in the precipitous cliffs, that had been invisible when viewed from the deck of the Donibristle. It was more than a cleft, it was a narrow, steeply ascending defile, and the only means of gaining the interior of the island from the harbour. Enclosed by bare walls of rock, never more than twelve feet apart, the path ascended by a series of zigzags, until at a distance of a furlong from the seaward entrance a natural barrier of granite terminated the gorge. Here, piercing the cliffs at right angles to the path, was a tunnel, the work of man's hands, driven through the solid rock. Defended by machine-guns, the gateway to the island could defy an army corps.

During German occupation the tunnel had been electrically lighted. The bayonet-sockets of the long-destroyed bulbs were still in position, while here and there broken insulated wire protruded from the rusted iron castings.

By the aid of torches made of resinous wood the guards illuminated the tunnel, through which a strong in-draught of warm air caused the lights to flicker and smoke.

On the principle that "you never know your luck", Burgoyne kept his eyes well open, studying the nature of the approach to the interior. One of the first objects that attracted his attention was a metal portcullis. It was already drawn up, and only a foot or so of the lower portion projected below the roof of the tunnel. Since no winding mechanism was visible, he concluded that above the tunnel was a large hall or cave, from which control of the portcullis and observation of the approach through the gorge could be made.

When about one-third of the inclined subterranean passage had been traversed, Burgoyne noticed that the wall on one side was running with moisture, and presently he saw an iron plate, about two feet in diameter, set in a metal frame and secured by six butterfly-nuts. It was obviously a valve, the seating of which was by no means water-tight, for two or three fine sprays were spurting diagonally across the tunnel, and forming miniature rainbows in the glare of the torches. As it was an inaccessible spot for a hydrant, Burgoyne formed the idea that the water formed part of the defences of the tunnel, and, if necessary, could either inundate the lowermost part or else set up an irresistible torrent against which no human being could stand.

Presently daylight showed ahead. The guards extinguished their torches by dashing them on the ground, and stacked the still-smoking wood in a niche in the wall of the tunnel. Passing under another portcullis, and turning sharp to the right through an inclined gulley, the prisoners arrived in the open air on the high land of the secret base.

Here they were halted. A pirate with the air of one having authority—he was equivalent to a barrack-master—carefully counted the prisoners, and began picking out a few at haphazard. Those he chose were subjected to a minute search, but luckily there was nothing found on them in the nature of arms or ammunition. Presently he stood still with his horny hand raised as if about to bring it down upon Hilda Vivian's shoulder.

The officers of the Donibristle were bringing up the rear of the column of prisoners, but behind were six of the pirates. Consequently Burgoyne was close to the girl, only the purser being between them. Alwyn saw Hilda shrink back. It was only a slight movement but nevertheless perceptible.

"That's done it!" muttered the Third Officer, striving in vain to think of a hurried plan whereby he might be able to save the girl without arousing instant and fatal suspicion.

But a deus ex machina had turned up at the critical moment. Black Strogoff, who had not accompanied the prisoners, had just emerged from the tunnel, and his imperious harsh voice was shouting for one Fernando. The barrack-master turned on hearing his name called and hastened to his superior.

When at length Strogoff dismissed the fellow the immediate danger was over. There was no further attempt to search the prisoners, but once more Burgoyne realized that there were limits even to the vagaries of fate, and that the presence of Hilda Vivian was causing complications that indicated more trouble at no distant date.

His anxiety was shared by the rest of his comrades. Up to the present, apart from the gruelling they had received during the one-sided engagement resulting in the capture of the Donibristle, they hadn't much to complain about. In fact it was rather amusing and exciting, this adventure, were it not that they were saddled with the responsibility of concealing the sex and identity of a young and pretty girl.

The march was resumed, the prisoners moving in fours with their guards on either flank and in front and rear of the column. The route lay over fairly regular grassland that for nearly half a mile rose gradually. Well on their left was a grove of coco-palms, otherwise the island seemed devoid of growing timber. Ahead lay a rounded hill, towering about two hundred feet above the general level of the plateau, while to the right were a number of wooden huts where the pirates lived when not required to be afloat.

There were other buildings that served as workshops. The pulsations of petrol motors, the rasp of circular saws, and the rapid beat of a pneumatic riveting-tool, clearly indicated the purpose to which these buildings were put. And Burgoyne had good reason to believe that the workmen were prisoners, since there were armed guards lolling about outside the doors.

As the Donibristle's men continued their enforced march, they passed patches of cultivated land and enclosed portions of pasture on which cattle and sheep browsed. There were men working in the fields, scantily-clad, bronzed and bearded fellows, who waved their hands to the new-comers. Some of them shouted greetings, but the distance was too far for the words to be audible.

"They're from the Alvarado and Kittiwake, I guess," remarked Phil Bra............