I felt very perplexed. Garth was a hard-headed Lancashire business man and there seemed to be a good deal of horse sense in what he said. And yet somehow....

I walked to the entrance of the cave and looked out. In awe-inspiring majesty the sun came rolling up from the east and the glistening beach was dyed in the hues of the morning. A few paces away Carstairs was shovelling sand for dear life. Already he had filled a dozen stout cotton bags.

"You may be right, Sir Alexander," I said at length. "I hope you are. But even if these gentry are concession-hunters we have to bear in mind that they are a cut-throat lot. They are quite capable of shooting first and of asking your name afterwards. I'm going to run up a little sand-bag parapet at the mouth of this cave. It commands a fine field of fire and will allow you or Carstairs to challenge anybody who comes within thirty yards. As soon as we've put the place in a proper state of defence I'm going out to do a little reconnoitring on my own...."

"My dear fellow," remarked Garth, sitting up in bed and nursing his toes, "to hear you talk you'd think the blessed old British Empire had ceased to count in the world. Foreigners can't go about murdering British subjects, you know. They'd have the Foreign Office on them damned quick, send a cruiser and all that sort of thing. However," he finished indulgently, "I'm quite prepared to hold the fort while you have a look round. I'm not sorry to have a lazy morning for, to tell you the truth, I'm so stiff from our climb yesterday that I can scarcely move!"

Rather with the air of Daddy helping his little boy to build sand-castles, Garth assisted me to erect a parapet at the mouth of the cave. There were not many sand-bags, but we helped out with some cases of tinned provisions, putting the sand-bags on top and then a layer of sand scooped out from the foot of our fortification. The screen of creeper across the entrance to the cave, while it obscured the view from outside, was not so dense as to prevent anybody within from commanding the approach to our stronghold.

Carstairs brought coffee and sandwiches and at my request filled my flask with brandy and brought me my automatic pistol and a couple of charges of ammunition. Then, turning my back on the sea, I once more struck out into the woods.

My plan was to make for the grave in the clearing. This should be the test. If our mysterious visitors were after the treasure I made sure I would come upon them in the vicinity of the grave. For, as far as I knew, the grave was the only indication they had to guide them in their hunt. It was still very early, and if I could gain the clearing unobserved, I would post myself at some convenient point, perhaps on the high ground beyond the grave, and await events.

I went forward very cautiously, my pistol cocked in my hand. I stopped repeatedly and listened; but, save for the hubbub of the birds in the trees, all was still around me. The burbling stream that fell from the high ground of the island to the beach gave me my direction.

I had reached a narrow ravine at the end of which was that flat rock whence, on the previous evening, Garth had described the ruined hut. On a slab which formed a convenient step to mount the boulder something white caught my eye as I came down the nullah. To my unbounded surprise it proved to be one of those cheap cigar-holders made of cardboard which so many Germans use.

I stooped to examine it. The holder with its quill mouth-piece, was quite clean and obviously brand-new. Therefore, it was no relic of the former visitors to the island. And it had not been there yesterday. I had mounted by this very slab to stand by Garth on the flat rock and if the holder had been there, I could not possibly have failed to see it.