A huge pair of bellows projected from the bottom of the kiln, worked by Raeburn stripped to the waist with the sweat pouring down his chest. Ballard was holding a mould in tongs, about to catch the drip from the furnace. Three small groups were watching: one of children and a schoolmaster, another of passers-by, and a third of four middle-aged and scholarly-looking men who might have been social historians or assistant directors of a folk museum.

They were getting their iron on the spot. At the back of the hollow and at the foot of the low cliff a band of ore showed plainly, which probably petered out too soon to have been of interest to a miner. A better demonstration for schoolchildren I cannot imagine. There was the whole process from the rock to the ingot.

One question, however, puzzled me. The home-made ingots were far from commonplace, but why should they be sacred? I guessed at a very tentative answer. The whole set-up could be a most ingenious blind like Marrin’s alchemy. Since there was no easy method of smelting iron secretly, he had decided to do it publicly. It was certainly ore from the surface rock which was being extracted, but if ore from quite another source (say, their revered Wigpool) went into the furnace, no onlooker would be any the wiser.

After returning to my car and driving it further between the trees, I slipped back to the free show. I wanted to know what the pair of metallurgists would do when they knocked off, and I had discovered a satisfactory lair from which to watch. There miners of unknown ancestry and language had been ruthless in chasing the ore, leaving behind a landscape of miniature crags which reminded me – though the sweeping, green shelter of a great oak confirmed that I was in England – of some painting of cypresses hanging in a grey Mediterranean gorge. A branch of the oak could be reached from a sharp pinnacle or rock. I climbed the tree and between the leaves had a perfect view of the furnace and the open ground.

The spectators drifted away, the high-brows remaining to the last and asking questions of Raeburn and Ballard, who were visibly impatient. Left alone, the two ran off the little remaining iron and cleared the slag. They showed no respect for the stuff and threw it into a pit. No suggestion of sacred ingots there! They then recharged the furnace with charcoal.

After satisfying themselves that no one was watching, they unloaded from their truck two little bags of a powdered mineral which looked like a very shiny coal and loaded the furnace with it. Raeburn, the bellows operator, swore. That was most irreverent in view of what followed but even devout Druids must be human.

‘God damn the bloody tin!’ he said, and turned again to the bellows.

So that was the metal of the sacred ingots. At first sight all that deception just to get a few slugs of tin seemed unnecessary. But one must remember that no smelting could be done secretly in the Forest, for the fire watchers would have been down at the first plume of smoke or the glare of the furnace by night; nor could it be done underground in the Wigpool workings. Ventilation would be a problem, especially if using charcoal.

But why not at Broom Lodge, teaching the craft to the whole commune instead of to the inner circle only? The answer lies in the mysteries of their creed, the confusion of past and future which also attracted the major, though he managed to find it compatible with Christianity. To Marrin and his followers those earliest workable minerals, gold, tin and copper, were to be venerated, and the process of ore to ingots was more sacred still. They were re-enacting the magic whereby the wizards of the tribe transmuted stones to arrowheads.

No doubt Marrin’s end-product was going to be bronze. Somewhere he had a source of the sacred tin. Copper he would have to buy – cheating, but it was most unlikely that he would ever find a vein of ore. Probably he was producing the alloy by means of his electric furnace, pending the elaboration of some more traditional method, to be occulted by oak grove, river mist or cave.

When dusk was beginning to fall the tin was flowing from the charcoal into the mould, enough for a small ingot of not more than three cubic inches. With ritual bows they set it aside to cool and solidify, and then retired to the cab of the truck to eat and drink.

I felt the presence of Nodens. I can only put the miracle down to him for I am not mischievous – at least not often. I decided to give these pagan puritans something to think about: an ingot really deserving veneration containing the protest of a happy neolithic hunter against distasteful industry. Inspired by a little chip of flint exposed at the foot of my oak, neat and thin enough to be an arrow head, though I don’t think it was one, I slid down quietly from the tree, spat on it for luck, rubbed it clean in my handkerchief and dropped it into the centre of the ingot so that it remained like a gem floating on the surface. Nodens was amused. Together we had created a myth. He is obviously a god whose divine nature it is to rejoice in the improbable. A finder of lost property could be nothing else, especially if he had stolen it in the first place.

When the two returned, their behaviour was even more exaggerated than I expected. They got the hunter’s message all right. After silent prayer they fetched a black velvet cushion from the truck and with the tongs reverently placed the ingot upon it. When the cushion naturally began to smoke, they recovered common sense and looked around for a safe high altar upon which the ingot might be placed, setting it temporarily on the flat top of the very pinnacle from which I had climbed my oak. It astounds me how the ultra pious of any religion will always choose some esoteric explanation of the otherwise inexplicable rather than ascribe it to human intervention. And that is a pity because it merely provides ammunition for those who scoff at the possibility of any unknown source of power.

The pair stood by their truck, discussing whether they should leave the ingot in the impressive position where it was or carry it back to Brother Evans. They decided on Brother Evans. Lord help the community I thought, if that pretentious fool had succeeded Marrin! The inner circle might accept him as High Priest, but I doubted if the main body of honest and innocent colonists would take his orders.

‘He’ll still be up there,’ one of them said.

I sneaked hastily back to my car and took the main road through the Forest which they, too, would have to follow unless they meant to go down to the river, which was unlikely. At a crossroads some four miles away I had a good chance of discovering where ‘up there’ was. They would turn left for Broom Lodge and right for Wigpool. If they drove straight on it would be to an unknown destination, and I dared not follow too closely.

I got away just ahead of them and parked in cover by the cross roads. They turned right. I gave them five minutes and cautiously circled Wigpool Common until I was approaching the Bailey Rock – or where I believed it to be, for the major’s report of his expedition had merely mentioned it. I could not find any good hiding place for the car and finally left it parked among others outside a Methodist chapel where some fête or committee meeting was in progress. Then I set out on foot.

Narrow lanes and open tracks seemed to lead in all directions. My chief fear was that the truck would find me, not I the truck. It was just after lighting-up time and I could only hope that the druidicals were good citizens and that the headlights of their oncoming truck would give enough warning for me to dive into the nearest ditch. I need not have bothered. This last finger of the Forest, pointing north, was so remote that I saw no wheeled vehicle whatever.

However, I did see tyre tracks when I was crossing an open field. Since they were recent and led to a spinney where there was no gate, I was interested. They could of course have been made by a farmer inspecting his fences, but he had neither returned nor driven off to either side and apparently had gone on into the spinney. In that case he must have cut the wire and replaced it. Close examination showed that he had done just that, and inefficiently – odder and odder and very unfarmerlike, unless he had gone in to haul out timber. There was no sign of that, so I climbed the barbed-wire fence – making my hard-worn trousers more disreputable than ever – and followed the tracks. They led me into a thicket of bramble and decaying pine trees, leaning or uprooted by the wind, and there was the major’s ancient Humber.