It looked very much as if Brother Evans had the same reactions as Marrin when threatened. Around the forlorn and friendly old car there was no sign of life except swooping bats. A detective no doubt would have come up with a dozen deductions, but the only one I could make was that the car must be at a safe distance from the shaft where the ‘geologists’ were prospecting with the full knowledge of the local villagers.

Prospecting for what? For gold, the major had thought at first. But that I was sure was nonsense. I myself had suggested that they were communing with spirits of the earth, which seemed to me quite a likely lunacy if there was a black lake somewhere underground. The answer now was more prosaic. They were searching for tin among the remaining pockets of iron in a mine long since deserted.

I reckoned that it was no good looking for the truck, which must have left long since if Brother Evans had been driven back to the site of the furnace to inspect and collect the fabulous ingot, so my only hope was to find the shaft, though it was nearly dark. I retraced my steps to the Bailey Rock and started again to explore the open country to the north of it, feeling that I had been too obsessed by the shadowy forest. I could find no recent heaps of spoil nor any hut. But there need not be either. A hole in a slope or low cliff would be enough. I remembered such a slope where half an hour earlier I had tripped over rusty bits of machinery overgrown by long grass. A small mine must have once been thereabouts, so I followed the foot of the slope.

I nearly walked slap into a sentry. He was sitting on a pile of pit props and away to his left was a jagged patch of black which had to be the entrance to the shaft. He heard me, but by the time he had got to his feet and started to flash a torch around I was lying flat in cover. A few sheep were sleeping not far off and I think he must have assumed that the slight noise was due to one of them, for he settled back on his pit props and lit a pipe. Working round him on lower ground, I crossed the wheel marks of traffic coming and going on a rough lane which confirmed that I was in the right place. So I crawled up the slope and made myself comfortable on the grass above the sentry, prepared to wait until something happened. As usual I was hungry, having had nothing since a breakfast of scraps in the den, but food could wait. By way of charcoal and schoolchildren I was on the scent of the golden cauldron. This was where it was, stolen by Evans and Co. before Marrin’s executors could get at it and now presiding over their futile ceremonies when it ought to be on a table in the British Museum with experts in committee around it to decide its date and provenance.

The truck returned with Evans, Raeburn and Ballard. They picked up the sentry and drove off after a short conversation which I was not near enough to overhear. A light drizzle of rain had drifted into the Forest from the Welsh mountains and under the low cloud, darkness and silence were absolute. I came down to the mouth of the shaft and walked along the passage until I was stopped by a wall of solid timbers reinforced by bands of iron, which had evidently been in place for years, presumably to keep out adventurous children. I could find no opening in the sides of the shaft offering a way round it and would have assumed that I was in the wrong place if it had not been for the scatter of pit props. Depressed by the wet mist and the difficulty of finding any concealed entrance in broken ground and thick night I gave up and tried to return to the Methodist chapel and my car. Tried, I write – for the country was like an open maze in which the shortest apparent route led nowhere and the longest way round was usually right. When I slumped into the driving seat I was tired out and damned if I was going all the way to the Chepstow car park.

I left the car on a forest track close under my hill and staggered shivering up to the den with the bag containing the tweed suit of that sane and ordinary economist, Personality No. 1. My own supplies of alcohol were finished. So was the major’s whisky. But after stripping off soaking clothes, his magnificent rug enabled me to get some tepid sleep with knees to chest. I hoped that he at least was fed and warm and dreaming of the Grail. It seemed unlikely. Remembering the Box Rock, I was obsessed by the thought of that black pool reported to be at the bottom of the workings.

In the morning I spread out No. 2 outfit to dry, though I could not see how the devil it was going to when even the midday sun hesitated to enter my safe but gloomy home. Then I drove into Chepstow and consumed an immense breakfast at the hotel. Resting in the lounge afterwards and reviewing the events of the night, the pile of pit props came to mind. I had not looked at them closely, but memory behind the eyes recalled ragged ends in all and a deep split in one. Now surely Marrin would have bought new and trustworthy props? He could well afford them and he was always thorough. The pile of props could be another of his ingenious frauds. That man ought never to have been a professional prophet. He’d have been famous as a designer of sets for the National Theatre. Under the pile, easily to be moved and rearranged, could be an entrance which by-passed the barrier.

I had at once to find the major, if only to relieve my own anxiety. Since my opponents were armed with religion rather than reason it was also essential to protect Elsa against incalculable reactions. I telephoned her at the estate office, insisting again that she should leave Broom Lodge at once and hand over her life to me as lover or husband or whatever she liked. She murmured that husband would do very well but then seemed anxious, depressed and obstinate. Land and workshops were running normally with the colonists as diligent as ever, but naturally there were questions on the minor day-to-day issues of policy and finance. Her uncle used to settle them all decisively and with common sense, and now the commune expected her to advise them. The man Evans had quietly taken over religious leadership but when it came to the practical running of the colony he left it to the various groups. Marrin’s will had been short and plain enough. He had bequeathed the estate to the commune.

But the commune wasn’t a limited company and it wasn’t a cooperative. What was it? Meanwhile, the bank manager was being as helpful as he could to such a good customer.

I pitied the bank manager. Evans might be sound on ritual and reincarnation but was not a man to understand that his authority in financial matters must be legal. And he would leave an impression behind him in the manager’s office that he was proud to live by barter or the begging bowl. I could only advise Elsa to refuse any responsibility and find some colonist – preferably a lawyer or accountant who had opted out of the rat race – with enough character to chair a meeting and obtain general agreement.

I thought that at last we should be able to get a line on Simeon Marrin’s income and what had enriched him, but there too he had covered his tracks.

‘What about the funds that he paid into the commune?’ I asked.

‘He drew on his private account, and they say there in London that he always paid in cash over the counter. They thought he must be some kind of a criminal until the manager here explained that he ran a monastery.’

The London bank was right. A criminal he was, robbing this ancient country of invaluable evidence of its past. I had said little to Elsa on this point, allowing her to half believe in the alchemy or, failing that, in a substantial profit from his goldsmith’s work. The truth might have involved me in admitting that I had been present at his death and in agonising her with the revelation that he had tried to kill me.

‘By the way, did Evans bring in a new sacred ingot this morning?’ I asked.