And for the first time, I was on location with John during the research and filming, staying together overnight either at Billa's or in hotels. It's like going away on holiday together — you get to know your presenter very well when you have to help him in the morning with the cuffs of his shirt , or go out with him to buy a capacious blue plastic mac from a gents' outfitters — his "Swaffham", he called it, after the town in which it was bought. Sometimes he would wear the Swaffham with a straw boater, which made an engaging picture. And there were excursions to dusty second-hand bookshops — Sir John's favourite, in Norwich, was The Scientific Anglian, which he called The Scientific Anglican.

An unexpected visitor was John's wife Penelope, who stayed for several days. Her presence seemed to unsettle him. The night she left he and I had dinner together alone, at the Maid's Head Hotel in Norwich. There followed the most extraordinary personal conversation I ever had with him, an outpouring of grief, guilt and regret about the sadness of his relationship with his wife and the alienation of his son Paul — "the Powlie", as he called him, who had left the country and would have nothing to do with him. For once the laughter was stilled, the public act abandoned. It was a gloomy evening.

But the filming itself still had magic. A high point came at Lound, in Suffolk but in the diocese of Norwich. Inspired by the richness and colour of the work of the Anglo-Catholic church architect Sir Ninian Comper, Betjeman astonished us all, in an unscripted piece to camera, by suddenly and spontaneously recalling Comper's lah-di-dah way of speaking — "my wark, don'cher know, in that charch" — and Comper's resemblance to Colonel Sanders, of the Kentucky Fried Chicken ads. Here was Betjeman on peak form — funny, surprising, incomparable (as he said of Comper).

Commentary writing stretched out longer than in previous years. But some of the verse he wrote had a depth of feeling rare in his earlier films:

Christ Son of God come down to me and save
How fearful and how final seems the grave.
Only through death can resurrection come
Only from shadows can we see the light
Only at the lowest comes the gleam . . .

John became uneasy and fearful as the commentary-writing progressed. There was tension, once even a row, in the cutting-room. To his normal paranoia about the response of critics was added an extra anxiety about how his churchy friends, and the Anglican community generally, would respond to some sequences.