After that the lads slept till nearly sunset.
It was a dark, starless night, much the same as the previous one. The air was heavy with moisture. Not a leaf moved. The off-shore breeze would not be likely to spring up until well after midnight. When it did the stars would be visible—and that would be unfavourable to the proposed operations.
At ten o'clock—that was the hour the lads took it to be—the sentry was relieved to the accompaniment of the usual display of torch-flashing. A period of tedious and uneventful watching ensued, until once more the flicker of an electric torch announced that the guard for the two hours from midnight was being posted.
"All ready?" asked Kenneth.
"Quite," assented his chum.
Armed with short heavy sticks, the two lads set out upon their nocturnal adventure. All was quiet at the huts. Although a light still burned in the pirates' living quarters the sound of revelry had died away, and the twanging of the guitars had ceased.
Treading softly and cautiously with their bare feet, the lads gained the pile of rusty ironwork that had sheltered Kenneth on his previous expedition. It was so dark that it was impossible to discern the figure of the sentry, but Kenneth staked his chances upon the probability of the fellow being asleep in his customary spot.
A reddish glimmer destroyed that belief. The fellow was awake and was smoking a cigarette. Moreover, by the fact that the glowing end of the cigarette was visible, he was either facing the spot where the chums lurked or else he was side-faced to them. His back was to the fence, and in that case it was impossible to spring upon him from behind.
"Isn't the fellow ever going to finish smoking?" thought Kenneth. It seemed as if more than an hour of the sentry's time for duty had passed, although in reality he had been "on" only twenty minutes.
At last a parabolic curve of light told the watchers that the Spaniard had thrown away the burning end of the cigarette. He did not light another, but after a brief pause he switched on his torch.
The light revealed the fact that the man was now sitting down and that he was consulting a watch. Finding that he had got nearly an hour and a half to complete his turn of sentry-go, the fellow lay down to snatch a brief rest.
Kenneth touched Peter on the shoulder. Together they began to crawl towards the spot where the man was—crawling so slowly and silently that Kenneth could feel his heart thumping against his ribs.
The Spaniard was breathing heavily, but whether he was actually asleep the chums were unable to discover, nor were they aware of the distance they had traversed until Peter's hand came in contact with the sentry's rifle.
By this time their eyes had grown so accustomed to the darkness that they could make out the huddled figure of the man; but not until they were within a yard of him did they spring to the attack.
Kenneth struck hard. He could afford to take no chances. He wanted to stun the fellow. He did. Without a groan the sentry rolled over on his side, and with the utmost dispatch the chums bound his ankles and wrists with his belt and scarf.
Holding his torch close to the man's face Kenneth switched on the light.
"By Jove! I believe I've killed him!" he muttered.
"No fear; he's too tough," said Peter, as he removed the Spaniard's knife and revolver. "Where are the keys?"
"I've got them," announced Kenneth, holding up a bunch consisting of one large and five smaller keys. "Hold on a minute while I gag the chap."
This little service performed, the chums groped their way to the gate, found the right key and swung the barrier open.
The outer door of the hut gave more trouble. The lock was stiff and obstinate. The hinges creaked dismally, but at last the chums found themselves inside the heavily-barred building. Closing the door, they switched on the torch, and found that they were in a sort of ante-room from which a corridor ran the whole length of the building and separated two rows of cells.
One key fitted each of the locks. The first cell was empty; so was the second. As the key was inserted into the lock of the third cell someone could be heard moving about.
"Don't make too much noise," said Kenneth warningly. "It's Peter and I."
The door swung open. Kenneth flashed his light into the dismal place, and in his surprise he nearly dropped the torch. The prisoner was neither Mr. Heatherington nor Captain Gregory.
Looking as terrified as a trapped rabbit was the chums' pet antipathy, Lopez!
Unable to recognize the two British lads—he was too agitated to grasp the fact that they had spoken to him in English—Lopez literally grovelled in the dust. Aroused in the dead of night he felt convinced that he was being summoned to execution.
Hitherto under the impression that Lopez was a prisoner in the Paloma, Kenneth was at a loss how to deal with the villain. At the same time the thought flashed through his mind that all the hazardous work the chums had done might be thrown away. The guards on the building might not have been posted on his father's and Captain Gregory's account, but solely to make sure that Mendoza's doubly-treacherous lieutenant was in safe custody. The real objects of the lads' quest might not be in the building, or even on the island.
"Pull yourself together, Lopez!" exclaimed Kenneth. "We aren't going to harm you!"
At the sound of young Heatherington's voice, the Spaniard looked up, blinking in the dazzling beam. Kenneth swung the light round and shone it upon his own features.
"Dios!" ejaculated Lopez.
Words failed him. He writhed like a stranded carp, trying to make up his mind how to bargain with the lads he had so vilely abused.
"Where is my father?" demanded Kenneth.
"In here—somewhere," replied the Spaniard. "Let me help, I will assist."
"No doubt," rejoined young Heatherington drily.
"Yes," continued Lopez, plucking up courage. "I will have revenge. Help you fight. I am no pirate. As for Mendoza, if I find him I will cut his throat."
"Lock him up and let's try our luck with the other cells," suggested Peter. "We've none too much time."
"Señores, believe me: I am your very good friend," said Lopez.
"Dry up!" interrupted Peter. "We've heard that yarn before."
"All the same I mean it. Let me go free and I swear by all the saints I will help you to regain your liberty. If I remain here then I must reveal everything to Sancho and the others."
"Very well, then," agreed Kenneth. "Clear out and make yourself scarce. I'd advise you to keep out of Mendoza's way. He'll be in a very bad temper when he finds us gone."
Kenneth held open the door. Lopez waited for no second bidding. He went.
"Isn't it rather unwise?" asked Peter. "He may give us away in order to curry favour with the other pirates."
"He's too much afraid of meeting Mendoza again to risk that," declared Kenneth. "Now for the other cells!"
The next two were empty, but on unlocking the door of the fourth to Kenneth's joy he found Mr. Heatherington sleeping soundly.
His son roused him.
"Come along, Pater," he exclaimed. "We've a lot to do and not much time to do it in. Where's Captain Gregory?"
"I'm here," replied the British skipper from the adjoining cell.
Peter released him. Gregory, his wounded shoulder almost healed, seemed none the worse for his detention. In fact he was physically fitter than when he had been sent ashore from the vessel he had once commanded.
Briefly Kenneth outlined the situation, and his future plans.
"If the boat's seaworthy, I'll navigate her to Talai," declared Captain Gregory confidently. "I suppose the rogues haven't removed her compass? There was one in the stern locker."