Early afternoon and I decided to look around a village on the other side of the escarpment. The easiest way to get to my destination was to go down onto the plain, round to the east and up into the hills again.

The temperature in the open air was incredibly mild. Once down on the plain I made good progress across the flat landscape. As you come to the edge of the plain, which is absolutely level, the escarpment rises up before you like a huge green wave of limestone, petrified at the last Ice Age. The road starts to climb upwards, the only point on this side where it can do so. On the cusp of the edge, among some trees, was the village I was heading to. On my left as I gained the summit was the Old Hall, tall and austere in dull red brick. This mansion was former home to the Clare family, Lords of the Manor for several centuries. Round the lanes I drove, doubling back in a circle until I reached the church. The door was locked, and when I asked at a nearby house for the key the key-holder (Mr Hughes, an elderly mathematics teacher) came out to show me round.

Unusually the church was dedicated to St Helen, mother of the Emperor Constantine (who made Christianity the official religion of Europe) and discoverer of the True Cross in Jerusalem, where she built basilica churches over many of the holy places. There is a legend (worked up by Evelyn Waugh in his novel Helena) that both Helen and Constantine came from the Roman province of Britannia although no-one knows precisely where. As the village was once the focus of a cult of St Helen it seems as good a candidate as any other place.

The approach to the church was through low double gates and along a wide gravel path towards the massive bulk of the west tower, solid and immense (Pevsner calls it domineering) with a square top instead of battlements. We entered by a door in the tower and once we were inside Mr Hughes silently pointed upwards - surprisingly you could see up through several stories, like the inside of a big square ornamental chimney, highly decorated in a way that was very striking (curtain arches on slender shafts and lots of dog-tooth carving).

The church had been restored by the Clares in the 1850s, but the money ran out so that the south half was smart and solid in ashlar stone by the architect Stephen Lewin, whereas the north aisle remained original sandstone, picturesque and crumbling. In the north aisle there was a seventeenth-century bust, the head surmounted with an incredible marble wig. There was also an Elizabethan sculpture, in the south aisle, to a young woman, her left elbow resting on a skull and her right hand trailing an extinguished torch (Pevsner regarded this relief as rustic and quaint, but I thought the morbid symbolism was depressing).

Mr Hughes knew a great deal about the history of the village, and I made lots of notes as he talked (I sometime feel a fraud doing this - if my work is ever published the acknowledgements section is going to be enormous). He showed me a side of the fourteenth-century font where there was a carved face of the Green Man, and then went into a description of the novel The Green Man by Kingsley Amis. I asked him about the Clare family and he described how the twentieth century had been too much for them and they had sold up and moved away.

"I have often wondered what becomes of families who lose their ancestral homes" ? he said philosophically. "Do they put it all out of their minds and build life anew, or do they wallow forever in nostalgia and regret?" ?

"Do any of them ever come back?" ? I asked.

"Oh yes" ? he said, "a Clare descendant came over from Kent about two years ago to have a look around. He knew every detail of the village, so obviously in his case the lost demesne had been preserved in family lore." ?

We went outside where thick dark yew trees were grouped about the church, atmospheric in the gathering twilight. The churchyard was right on the edge of the escarpment. The view from this point is famous, and on a fine day you can see all of the plain and across the inland sea and beyond (into the haunted county). Below the church, so that the roof was level with our feet, was the eighteenth-century fa ade (which Pevsner says overlays a more primitive construction) of The Old Rectory, looking like a dolls house, surrounded by a garden of hedged "rooms" ?.

It was still reasonably light as I drove down from the escarpment. Water seemed everywhere - water lying on the fields and in the full ditches, water hanging in the ominous clouds overhead, and water falling as a light rain. The presence of all this moisture gave me the impression, as the car reached the level, that I was being immersed in the prehistoric sea that once covered the plain.