Denis was my guide to and from the new out-of-town Lidl superstore at Salernes in Provence. I drove. The road was a smooth ribbon of asphalt newly laid through an ancient forest of dwarf oaks. The in-car conversation with Denis was, as usual, easy and undogmatic and wide-ranging, which is the only sort of conversation I am capable of, for I can never remember what my opinions are, let alone which set of beliefs gave rise to them. In this uncommitted way we drifted aimlessly on a gentle swell until we bumped up against the subject of ghosts. I had never seen or heard or felt a ghost, I said. Neither had I met anyone who had. So no, I didn’t believe in them. Denis had and did, however, claiming to have frequented two houses that were quite definitely haunted.

He once rented a house in Hampshire and became friendly with a neighbouring family who lived in a very beautiful old house that was, in his words, ‘haunted to buggery’. The husband was, among other things, a musician with an academic interest in medieval music. One day his son, who was then about nine or ten years old, sauntered into the house from the garden singing a quaint song, which his father recognised as an obscure old English folk song. He asked his boy to sing it again for him, which the boy did. ‘Where on earth did you learn that?’ said the flabbergasted father to the son. ‘That friendly lad in the garden wearing funny clothes taught it to me,’ said the boy.

One Sunday, the musician and his wife invited friends over for lunch at one o’clock. One o’clock came and went with no sign of their guests. At two o’clock they gave up waiting and started lunch without them. At three the musician rang the home of the missing couple to find out what had happened. They were in. The wife answered. ‘We drove up to the house at ten to one,’ she said, ‘and there was such a colourful crowd in fancy dress on your lawn that we thought it was a children’s party or something and that we’d got the wrong Sunday. So we turned around and came home.’

At Lidl we filled our trolley mainly with Lidl’s own-brand gin at an incredible six euros a bottle. Coming back, Denis said, ‘Would you like to see the first house I bought when I came to the area?’ Under his directions we made a small diversion and parked at the foot of an unmade track, from where we could see a mansion perched on the side of a forested hill about half a mile away. The sight of it clearly moved him. I killed the engine and we sat in silence and stared at it. It seemed to me a gloomy-looking place. ‘How old?’ I said. ‘Oh, not very,’ he said. ‘A hundred and fifty tops.’ There followed another long, contemplative silence, punctuated by the spastic ticking of the cooling engine.

Then he said, ‘And this is the other haunted house I’ve known. I remember the day my wife and I arrived. In the afternoon I took a walk in those woods and saw a magnificent stag standing not 50 yards away, looking at me, as I imagined, significantly. He was the only one I ever saw. I took him as a favourable, welcoming omen, which by and large he was.

‘But there was a woman in Victorian clothing who would regularly appear in the kitchen then disappear through the wall. And one day I was working in the upstairs room that I used as a workshop when I heard the most awful, heart-rending scream — a woman’s scream — which literally made the hairs on the back of my neck stand on end. My wife heard it too. A bit of local historical research showed that the house was a hunting lodge built in the late 19th century by a Marseilles banker. Tragically, a daughter suffered brain damage due to dehydration after falling asleep in the sun, and the banker kept her locked in the cupboard. The scream came from where the cupboard used to be before it was walled over. Of course we never breathed a word to anyone in case we ever wanted to sell the place. Yet in spite of the apparition and that horrible scream, the atmosphere of the house wasn’t unhappy.’

That this Cambridge-educated former Special Branch officer (then cynical manipulator of the public mind as a television commercial producer) was a believer disturbed my disbelief not at all, however. Much more fantastic to me than any spirit world, and relevant, was the huge amount of Lidl’s own-brand alcoholic spirit, at an incredible six euros a bottle, that we had clanking around in the boot of the car.