It was a rude timber shack with a door and a window, the interior choked roof-high with growing ferns. The timber flooring had rotted away and through the mouldering planks the jungle had thrust its shoots profusely as though to claim its own. But in one corner, where a roughly-carpentered bedstead of timber stood, some attempt had apparently been made to thin out the ferns for a space. On the bed there lay a rotting blanket; on the floor close by some empty canned beef tins red with rust. The blanket practically fell to pieces at the touch. It was not marked and, though we groped pretty thoroughly among the ferns, that was all we found in the hut.
"There's nothing here," I said at last. "Let's have a look round outside. I am wondering...."
The words died away on my lips. I had reached the hut door, my face turned towards the farther edge of the crater, the opposite side from that by which we had descended. A hundred and fifty yards from where I stood a large timber cross was planted in the ground. Between it and the hut lay a great isolated boulder which had probably concealed the cross from our view when we had climbed down into the hollow.
For a moment I could hardly speak. I have seen the proud loneliness of Cecil Rhodes' resting-place in the Matoppos; I have stood (like everybody else) in the amber light that bathes Napoleon's tomb "on the banks of the Seine among this French people I have loved so well." But I have never seen a sight more impressive than that solitary grave on that desert island set down beneath the little round canopy of blue sky which seemed to be borne by the lofty frowning cliffs towering all around. Beneath that plain wooden cross, I told myself, in a silence unbroken by Man, lies the Unknown. It was a mighty impressive thought.
A rudimentary path, still to be discerned through the all-pervading undergrowth, led, round the boulder of which I have spoken, to the cross. The grave lay out in the open in a little patch which had been cleared of ferns. As we came up to it I noted, with an odd little trick of the memory, that the grey and weather-beaten surface of the cross was highly polished, even as the beach-comber had described, by the action of the sand grains blown by the wind from the seashore.
Fashioned out of two baulks of timber wired together and solidly implanted in the ground, the cross stood at the head of a long hillock of earth. On the grave lay, face upwards, a small round mirror and, a little beyond it, an empty bottle, uncorked, which had fallen on its side.
"You see," I remarked to Garth, "it's just as Adams said!"
I stooped to pick up the mirror. Then to my surprise I saw that it was wired to a timber cross-piece which ran out from the cross as a support. It was a little glass set in a metal frame.
"It looks like a shaving-glass!" said Garth.
I did not undeceive him. I am not a secretive person by nature but by training. The very character of Intelligence work—the careful sifting of every apparently insignificant scrap of evidence, the lengthy process of surmise and deduction—tends to make one discreet, even when dealing with one's familiars, until a plain statement of fact can be drawn up. So I did not tell my host that, the moment I saw that the glass was attached to the cross, my brain leaped at the first clear clue to the Unknown's baffling cipher.