Having cordially accepted the string-of-presents theory as expounded by Major Quixote – there’s a flaw in it somewhere, but it does account for visions of the past – I started on the strawberries and asked him how much he knew of Marrin’s movements.

‘Too busy to leave the place in the day much unless he’s off to London to sell his trinkets, but he does go out at night when the tide serves his purpose. Meditating under water they say.’

‘And if I want to leave a message for you, how shall I do it?’

He asked if I was sure that I could find again the ragged stump of the sapling which he had cut. Yes, I was sure.

‘Then bury your note alongside and put a stick to mark it. I’ll do the same.’

It was now twilight. I thanked him warmly and got up to go.

‘Any trouble with alcohol?’ he asked.

‘No trouble.’

‘Good! Take the whisky bottle.’

I thanked him warmly and left, but did not go home. First I watched the major drive away; he was shaking his head and talking to himself when he got into the car, perhaps in sadness at the criminality of his enigmatic friend. Then I set out on foot for Broom Lodge. I reckoned that if there was anything at all in this meditation over the flowing tide, Marrin, after last night, would have a good deal to meditate about and might get down to it straightaway.

It was nearly dark when I arrived, so that I was perfectly safe in the garden on the open front of the house. Lights were on in the hall for those who preferred earnest discussion to bed; lights were going off upstairs as craftsmen and farm hands who would be up early settled down to sleep. It occurred to me that if Simeon Marrin wished to give his disappearances an air of spiritual mystery he would slip away at the back into the shadows of the trees rather than walk out of the front door like ordinary humanity; so I made a circuit into the woodland at the back and waited.

A little before midnight, eight persons left the house and took the forest track into the darkness. I could tell by his height that one of them was Marrin, carrying a box. Another appeared to be carrying a trumpet. When they had passed, I followed. I had no experience of this sort of prowling, but it seemed simple enough so long as the pursued made enough noise, however slight, to cover the sound of the pursuer. Of that there was little, for I kept to the soft grass in the middle of the ride and was ultra-careful where I stepped.

It was soon plain that their destination was not the river but somewhere deep in the Forest. They stopped in an open space between the oaks where the young green bracken was thick over the brown mat of last year’s fronds. Marrin used a powerful flashlight to satisfy himself that there was no one in the immediate neighbourhood, but omitted to search behind tree trunks. It looked as if an open-air ceremony was about to begin. That did not surprise me. I had thought all along that the commune was very secular – plenty of casual discussions and meetings but, apart from the hours of meditation, no set ritual. I had expected from that druidical inner circle robes, invocations and other impressive mumbo-jumbo.

Now I got it, and in that setting it was indeed impressive. The trumpet was not a trumpet but the torch of old times. When stuck in the ground and lit, it threw a steady, smoky red light over the proceedings, allowing me to see that Marrin was clothed in a long blue robe. He opened the casket which I had seen in the laboratory and took out the golden cauldron, lifting it high above his head by the two handles with the gesture of a priest. Its weight was obvious, and I was again convinced by its triumphant simplicity that it was ancient. While one of his seven tonsured acolytes chanted in a low voice some language that I think was old Welsh – as near as one could get to the vernacular in which British seamen and miners would have prayed to Nodens if they had no Latin – Marrin passed the cauldron to another. A third who carried a covered pot lifted the lid and poured the contents into the cauldron. A strong, intoxicating scent of herbs and honey came downwind to me. Meanwhile the remaining four stamped out a circle in the bracken with Marrin in the centre. When it was complete, one of them passed the cauldron back to Marrin across the circumference.

The object of the rite, so far as I could guess (and since the language of gestures is universal one tends to guess right), was to propitiate or help the spirits of the dead. I don’t wonder that Marrin had called a conclave of adepts. I’m going to need quite a lot of propitiation. He did not of course mention my name. To him alone the ceremony had special meaning.

The seven adepts appeared to see and to bless some sort of apparition in the air above the bowl. The curious thing is that I saw it myself: a diaphanous, moving figure like a pencil of mist rising from the ground. My brain of course was affected by the brew in the bowl and mistranslating the message from the eyes. I have no doubt that Marrin saw it too. He was not play-acting this time. He believed so absolutely in himself and his rite that he created the illusion for the rest of us, perhaps by telepathy and the hypnotic effect of the drug. Proof that it was illusion? First, that I wasn’t dead at all and only he thought I was. Second, that all the codswallop of solemnities could produce the desired effect on a profane, sceptical outsider, unclean ritually and in fact.

They spent about half an hour on the In Memoriam service and returned to Broom Lodge as secretly as they had set out. I followed, in order to see what door they used in case it ever came in handy, and then walked home to my den – myself feeling a ghost wandering among trees and tracks, for on the way I did not pass man or sheep, partly due to the late hour and a slight drizzle which had started.

Tucked up in my outside lavatory with the major’s rug over me and a good swig of his whisky inside me, I thought over the curious scene. Was such liturgy at the heart of Broom Lodge? I thought not. It was confined to the druidical drop-outs – a vulgar nickname of mine, considering the woodland features of the ceremony handed down from pagan and poetical Britons. I knew the names of four of them: the chanter, Evans, a sulky fellow who strutted like a hierarch which Marrin never did; Raeburn, who had poured the brew into the cauldron, an excellent craftsman with a sense of humour in daily life; Ballard, the curate-looking chap who had been digging up tulips when I first arrived; and Carver, a compact little holy man who had passed the cauldron to Marrin.

Evidently it was such a rite as this which the major suspected and considered a blasphemous misuse of the cauldron, far worse than the half-pagan heresies somehow related to the mysteries of metals. Transmutation I did not believe, but those herbs, of which the heavy scent flowed off under the branches further than the smoke of the torch, suggested that Marrin was a devoted student of ancestral pharmacy and that the laboratory itself was no pretence.

I slept long and late, recovering from the previous two nights and such exercise as I had not taken since tracing the once-cultivated fields on the coast of Greenland. I found myself stiff but fit. The first job was to buy supplies from somewhere miles away where I had never been before. Coleford to the north and on the edge of the Forest seemed a likely spot. It turned out to be an ugly little Victorian town like most of the mining settlements, but with everything I needed. Having noticed a fire-watching tower which commanded most of the Forest, I decided against using my ruined hearth in case the plume of smoke was noticed, and bought a Primus stove and a frying pan. With eggs, butter, cheese, bread fresh from the oven, meat, green stuff and a variety of cans, plus a bottle of brandy to disguise the taste of coal in the sparkling water from the nearest stream, I returned home to my plantation.