I saw only him for the fraction of a second, a young man, tall and slim and very blonde, in a shirt open at the neck and riding-breeches, his head bared to the storm. The water streamed off his face and clothing; but he stood perfectly still in an attitude of reverence. In that wild setting of tempest-swept rocks the apparition seemed like some spectre of the Brocken. Or one might have thought that the storm had summoned forth the Unknown himself from his grave.  
The vision fairly staggered me; for my mind was imbued with the idea that the island was uninhabited. But my brain keyed up by the events of the day, did not dwell for an instant on any supernatural explanation of the apparition. I promptly asked myself whether, after all, there were people living on the island or whether the man I had seen had, like ourselves, landed from some passing ship.
 
But then, without warning, there came an ear-shattering metallic crash, as though a big shell had exploded beside us, the earth shook and a perfect tornado of wind and water descended upon the clearing, clawing and tearing at the hut until it seemed as though the beams of the flimsy structure to which we desperately clung would be wrenched from our grasp. The inky-black sky appeared to split across in a jagged band of light which again showed up the clearing as bright as day. But now the tall wooden cross stood aloft in solitary majesty once more. The figure at the graveside had vanished and the clearing was entirely deserted. I asked myself whether the apparition had not, after all, been the figment of my imagination. Garth had seemingly remarked nothing so I resolved to say nothing about it unless he should ask me.
 
But now, amid the grumbling and rumbling of the thunder receding into the distance, the storm was passing. The air reeked with the stench of sulphur and I guessed that the appalling crash we had heard had marked the fall of a thunderbolt. Slowly the light was coming back and, though the rain yet descended in torrents, the downpour was much less heavy.
 
We were in a sorry plight, the pair of us. Our thin garments clung to us like wet swimming suits and our teeth chattered in our heads.
 
"We appear to have timed things very badly," grumbled Garth, wringing the water out of a corner of his tussore jacket. "We had plenty of warning of this storm. I should have thought we might have managed to have got back to the camp in time to escape it...."
 
I wiped the water out of my eyes and grinned.
 
"Oh," I said lightly, "a ducking won't hurt us! Look, the rain's stopping already...."
 
"I am not complaining about getting wet," observed Garth with an air of dignity which went ill with his bedraggled appearance—he was squatting on his hunkers squeezing out his hat—"I can, I believe, put up with the hardships of an expedition like this as well as any man. But I do think the—er, staff work this afternoon leaves something to be desired. To be wet to the skin an hour's tramp from camp may amuse you, Major Okewood, but the prospect of a heavy chill does not strike me as being funny in the least!"
 
In high dudgeon he placed upon his head the shapeless mass of soggy felt which had once been a hat.
 
"I vote we make a move for the camp," he proposed. "That is, if anything is left of it. I should not be in the least surprised to find the cave under water, our stores ruined and Carstairs drowned—or struck by lightning, as like as not. I don't wish to seem inquisitive, Major Okewood, but might I inquire what progress this afternoon's unfortunate jaunt has brought to your investigations?"
 
I was rather nettled by the line he was taking, and the way he manhandled my name irritated me.
 
"You needn't worry," I retorted curtly. "I'm perfectly satisfied so far!"
 
"Indeed," replied the baronet—he was struggling to free himself from a giant creeper which had firmly fixed itself about his sodden clothes. "I am sorry I cannot share your optimism. But then I'm wholly in the dark—maybe, it's just as well—about this infernal wild-goose chase. Damn it," he cried suddenly, "can't you lend me a hand to get this blasted root off my legs?"
 
I hastened to release him, fuming and fretful.
 
"We shall be home in no time," I said soothingly to humour him, for he was like a spoilt child, "and you'll see what marvels Carstairs has accomplished in the way of making us comfortable. And you needn't worry about the cave. It's splendidly sheltered. Not a drop of water will get in!"
 
Night was falling by the time we emerged from the steamy atmosphere of the sopping woods and made for the faint glow of light which shone from our cave. Carstairs met us at the entrance. He had fully justified my prophecy to Garth.
 
Our beds were made up, one on either side of the cave, and our washing and shaving kit laid out on toilet tables improvised out of boxes neatly covered with clean white paper. Hot water steamed in our wash-basins and a dry change of clothing was laid out on the beds. In the centre of the cave, on packing-cases covered by a white damask cloth, the table was set for dinner. A hurricane lamp, placed in the centre, was flanked by enamel cups from the picnic basket filled with bright flowers and on the ground a bottle of Garth's excellent champagne was cooling in a bucket of spring-water.
 
We lost no time in changing, and within a quarter of an hour were sitting down to what was, in the circumstances, an extraordinarily well-cooked meal. Garth's ill-temper melted perceptibly and it was with the utmost cordiality that he raised his glass and pledged the success of the expedition. The ingenuity of the incomparable Carstairs had so completely reproduced the atmosphere of civilisation that it was difficult to believe we three were dining on a lonely islet in the middle of the Pacific.
 
After dinner Garth yawned expansively and opined that he would turn in. The unwonted exercise of the afternoon, he declared, had fagged him out. But I had no mind for bed. My brain, stimulated by the unaccustomed environment, was active. The apparition at the graveside during the storm had profoundly disquieted me and I wanted to think. So I strolled outside for a solitary pipe beneath the stars.
 
On the shore I found Carstairs, pipe in mouth, contemplating the sea. I love the old-time Regular, such as Carstairs, with his twelve years' service in the Sappers, was, his loyalty, his quiet efficiency, his eminent common sense. And as between two professional soldiers a bond of silent sympathy had established itself between Carstairs and me. We had not even discussed the incident of the drink I had given him that night on board the yacht. Having ascertained that Carstairs was practically a total abstainer, I gave Mackay a hint to forget all about his nocturnal diagnosis. I had my own theory about that drink and perhaps Carstairs had his; anyway, we did not discuss it.
 
"Grand night, sir!" said Carstairs, taking his pipe out of his mouth as I approached over the sand.
 
"Wonderful!" I commented. "Good spot this, Carstairs!"
 
The man did not reply. He was sucking on his pipe which did not seem to be drawing well.
 
"It's a uncanny kind o' place, as you might............