'For once the words come up to the reality of Mercury,' he said. The rough-hewn face might have been carved from his own grim cliff. The muddy skin was taut over the bold bones beneath, a jutting jaw to frame the wide mouth, now clamped shut, the large eyes and arrogant nose.
He went on: 'To enter the Glory Hole you need two things; a calm day and a dead low tide. I have never known the two coincide. In one year here there are perhaps two or three calm days. Then you find the tide is wrong. No, I have never been in.'
There must be an entrance from the island itself,' I pressed him, 'some gap in the rocks…'
'There is none, none whatsoever.'
'When the going is tough, that is the way I like it in my line,' I said. 'I want to take a look inside the Glory Hole and I mean to. I wish I had one of those fancy American deep-sea cameras.'
'But you haven't got one?' The voice was relieved, though curious.
'Hell, no,' I said. They cost the earth. The Praying Mantis is a shoe-string job — essentials, but little else.'
Minnaar said, 'We could send in a couple of electronic flotation drums and track them with the Hydrodist. We might manage an outline of the interior…'
That wouldn't tell us much,' I said. 'It's not the shape I want, but what is inside the shape. It can't be so deep — the island itself is not more than a quarter of a mile wide. What surprises me is that the cavern does not extend right through to the other side. I'd expect that, the way the waves must eat away the rock — always coming from the same direction.'
The tide and the waves… I don't see how you can ever find out much,' said Shelborne.
I let myself be carried away by the problem. 'There's a gadget called a Kullenberg corer. It collects a long shaft of sediments from the ocean floor a couple of inches across and up to seventy feet long. I naturally can't afford a thing like that, but I built a modified one myself, which is pretty useful. If there is diamond gravel, I reckon I have a good chance of locating it.'
'If you want caverns, I can take you up the coast to half a dozen bigger and better than Mercury's Glory Hole,' Shelborne said quietly. 'My cutter is tied up in one of them, you remember, I told you. They are accessible, too.'
'In my survey area?'
'At least two of them are.'
'Have you prospected the sea-bed round Mercury?'
He parried this, very coolly:
'Of course — I told the court so. Grabs and dredges,' he said deprecatingly.
And you — found?'
'My dear fellow,' he replied with a shrug. 'What do you expect with that sort of equipment?'
I said, 'You know, I suppose, that the guano islands were once prospected by a government team?'
'Yes. They found diamonds on Possession Island — 223 carats, to be exact, worth Ј500. The team also went to Penguin Island, Ichaboe and, you'll be interested to hear, Mercury. Not a diamond anywhere except on Possession.'
Minnaar, feeling the effects of the stiff brandies in his coffee, interjected, 'But one of the islands yielded diamonds. That means it's worth trying the others…'
Shelborne ignored him. 'The entire prospecting project cost Ј825 and the value of the diamonds they found was Ј500. That speaks for itself. The true wealth of the islands is their guano, the sea-birds, the seals and penguins. They are my first concern…' He glanced at his watch and the defensive note went from his voice. 'Come, we've got to get up to the summit. ETA is 4.30.'
'What the hell are you talking about?' I asked.
The black mood was gone and he seemed like a schoolboy starting a holiday.
'I want to know what sort of bottom there is in the bay…' I began to say, but he rose, smiling.
'You can have your sea-bed and its diamonds. Come on!'
We climbed the steel steps behind the huts. Shelborne moved at a great pace, Minnaar and I trailing. The defined path ended 150 feet above the hut. From there onwards to the summit it was simply a series of zigzags through sharp rocks.
Minnaar and I stopped at the same moment, hit by the realization that the whitened rocks and hollows, scuffed by countless thousands of beaks, wings and talons, were empty.
There was not a bird to be seen.
I tried to catch up with Shelborne to ask him, but he moved too fast. Slipping and puffing, I needed all my breath. The wind blew the sealskin collar so that it masked the lower half of his jaw. The words of the prophet rose of their own accord into my mind — a diamond harder than flint have I made thy forehead! And his was a forehead and head for an artist. Diamonds! All my analogies were of diamonds. What had Shelborne really found? How much did he know? Why his passivity when I would have expected hostility, or at least his non-cooperation? His facts and figures about the official prospecting team seemed very glib.
We switched into a long transverse gully which split the island half-way to the summit. The late winter afternoon light was fading, leaving the rocks an unlovely grey. The island sloped from left to right, the highest part being on my left, or south-west, facing the entrance channel, tapering away on the right to three small isolated rocks which were linked to the main island by plank bridges. Shelborne's pace was killing. We skirted an enormous rock, which looked like a crucified man, and on to the summit plateau. Minnaar and I were gasping when we joined Shelborne there.
'Where are the birds?' I had begun to ask, when Shelborne interrupted me. His words were strange after what I had been thinking scrambling up:
'Do you know what the ancient meaning of the word diamond was?' he asked. 'Untameable. You can't tame it by fire or blows. Mercury is like that, too. Look!'
Minnaar and I gulped lungfuls of the south-west wind. Far below, thousands of seals had cornered a rocky platform on the sea's edge. The rock was polished black by their bodies.
Shelborne glanced at his watch. 'Look!'
'Jesus! exclaimed Minnaar. The ship!'
I saw the massive line squall creaming in from the north-west. A cold sensation of fear gripped me. I knew what that white meant — a squall vicious enough to suck up the sea; and now it was racing in towards our anchorage. It seemed to stretch endlessly, angry, white, grey-white.
Shelborne was relaxed, exultant. 'They're coming!'
The ship!' I got out desperately. 'Shelborne…!'
He gestured to the onrushing squall. His voice had a curious intonation. 'Four-thirty! You thought — I saw it in both your faces — that I was lonely, alone for my twenty-odd years on Mercury. I have been, indeed I am, when — ' he waved at the oncoming mass — 'the birds are away.'
'Birds!' Minnaar said it in a quiet, wonder-filled way, as if there had been no hard-case years, no brandy-filled tramping the coast.
The whole sky was filled with a fluid whiteness of feathers, wings and flight.
The glory of the stupendous sight was upon Shelborne. 'For twenty years they have returned from their winter migration at exactly one bell in the first dog-watch,' he said. 'Here they are today. They've been away for four months now. Soon Mercury will be white with guano, but we won't start scraping until a thick enough layer forms. I'm sending my team of workers off tomorrow to Hollam's Bird Island. I'll be alone for the next two months.'
The great snow descended. Flake by flake the solid cloud disintegrated into fragments, individuals. They swooped unerringly, Shelborne told us, to last year's nest, each knowing his place. Gannets, duikers, cormorants, solan-geese — the whole air chuckled with their welcome-home shouts. They came unafraid to our feet, vocal, quarrelling. Birds! Birds! Birds! There was not the smallest bare patch to be seen anywhere: Mercury had become one great breeding-flat, and the rocks were white with millions of them.