I remained rooted to the spot. The droning chant went on. How far the singer was from me, it was impossible to estimate; for a voice carries far at night—he might be anything from twenty to a hundred yards away. There was nothing to do but retire;.... in that clammy, steamy darkness any idea of stalking a man was out of the questions.  
All the events of the past week came tumbling into my brain. They had tracked me down, then, and now I was at grips with El Cojo's famous organisation.... But this was no time for speculation or surmise. I could think matters out afterwards; for the moment I must keep my mind clear and concentrate on getting out of this dense jungle quietly and quickly.
 
Now the humming had ceased. Did it mean that the singer was moving forward? I strained my ears but could catch no sound other than the rustle of the leaves as they dripped moisture. To move in silence through the clinging undergrowth was, I knew, a thing impossible. An old memory of capercailzie shooting in Russia came to my aid. One stalked the male bird perched on a tree-top as he uttered his love-call to the females at the foot. When he called one moved; when he stopped, one halted.
 
The droning recommenced. Did my ears mislead me? It certainly sounded nearer now. My compass lying flat in my left palm, I moved swiftly forward, heading for the west. When the humming ceased, I stood still and pushed on again as soon as it was resumed.
 
A horrid thought assailed me. Was the singer the spy whose unseen presence had impressed itself on Carstairs that evening? Or were there others? Had the cordon let me through only to draw in upon me as I returned? I had no weapon; for I had given Carstairs my revolver to clean and oil on our return from camp that evening after our wetting.
 
The crooning chant had grown much fainter. I must be drawing away from it. I paused an instant to wipe away the sweat which was pouring into my eyes. Then came a sudden crash in the undergrowth close to hand. I steeled myself to the encounter, getting my back to a tree and striving—but how vainly?—to pierce with my eyes that bewildering pall of darkness. Another heavy crash, a frightened squawk, and I breathed again. It was only one of the island pigs whose nocturnal rambles I had disturbed.
 
And now for full five minutes I had heard the singer no more. The forest was getting lighter, and like blissful music there came to my ears the distant surge of the sea. Presently, without further incident, I stepped out on the beach not more than twenty paces from our cave.
 
A black shape rose out of the darkness at my feet. It was Carstairs. I put my hand over his mouth and drew him into the cave. The place re-echoed with Garth's rhythmic snoring.
 
"You were quite right, Carstairs," I whispered. "There is someone in the woods back there! Have you heard or seen anything?"
 
"No, sir!" the man returned. "But I was that certain sure there was somebody round the place that I nipped in and got a pistol to sit up and wait for you...."
 
He showed me the automatic in his hand.
 
"I don't like the look of things at all, Carstairs," said I, "and that's a fact. I'm not getting the wind up over a lot of shadows; but I don't propose to risk having the camp rushed. You've got some bread-bags and the like, haven't you? Well, get one of the shovels and start filling 'em with sand, will you? If we can run up a bit of cover round the entrance to the cave, one man ought to be able to hold it against all-comers. Meanwhile, I'll wake Sir Alexander here!...."
 
It is a little embarrassing to rouse a man up out of his beauty sleep and tell him you have been keeping essential facts from his knowledge. However, I could at least honestly claim that, until that moment, I had nothing stronger than suspicions to go upon.
 
Propped up on his elbow, Garth heard my whole tale just as I have set it down here, from the moment that John Bard identified Black Pablo with the man who had kept watch outside Adams' hut down to the strange happening in the woods that night.
 
"Just what we are up against, Sir Alexander," I concluded, "I don't know. But we're here for a specific purpose and I feel sure you will agree with me that we should not allow a band of filthy cut-throats to deter us from it!"
 
"Certainly not, my boy, certainly not!" declared the baronet. "As a matter of fact, I cannot really believe that these fellows really intend us any harm. After all, we're British subjects and a little of Britain goes the deuce of a long way in these parts...."
 
"Very possibly, sir," I replied, "but you must remember we do not know how strong this party is. Force is the ultimate sanction of the law, they say; but on this particular island British prestige is backed up by exactly three very imperfectly armed Britishers...."
 
"If you'll allow me to say so," Garth broke in pompously, "you go rather fast. From the accident that you overheard on an island which we previously believed to be uninhabited a song you heard sung (in peculiar circumstances, I grant you) at Rodriguez, you appear to assume that the men who murdered Adams have landed on this island. Your song may be a popular favourite in Rodriguez; everybody may be singing it. Have you thought of that?
 
"If this figure you saw at the grave and this man whom you heard humming in the forest belong to this mysterious gang led by El What's-his-name, then they must have followed us here. But how did they come? We have seen no steamer. If, on the other hand, the song incident is capable of some simple explanation such as I have suggested, your last valid link of evidence connecting these mysterious visitors of Cock Island with El Thingumybob's gang snaps."
 
This was very ingenious. But it didn't convince me. The intonation of the singer in the forest was identical with that of the man in the lane. Of that I was sure. Besides, in the back of my mind lurked a half-formed suspicion about Custrin which I had not as yet thought proper to communicate to the worthy cotton-spinner. And, as for having seen no steam............