'The director was a man called Davis Thighbold. He called and said he was a ‘huge fan’ of the book. I was flattered. Davis was a charismatic man and as I was to find out something of a con artist. He came to our house and Crystal cooked for us. It was a lively evening. Davis was a raconteur. He said he’d read Escaping The Clutches of Satan’s Claw as a teenager, picking up a copy in the school library. There was finance in place for a film adaptation. Davis didn’t have much experience. He’d directed a cat food advert. After dinner we were in the study and Davis said he had had a screenplay in the boot of his car. He fetched it. I studied the documents and was frankly appalled. The title had been changed to The Mark of Satan’s Claw. I protested that this undermined the essentially positive message of the novel which was the theme of escape. Davis laughed and must have assumed, falsely, that I was joking. I read on. It was sexualised and smutty: Carry On bilge. But there were other considerations. Crystal and I were about to lose the house after the taxman came calling. I said that with some corrections and amendments the screenplay would be just about viable. He agreed. When I went to set the film, with some trepidation, I realised none of my changes had been made. I regretted giving my blessing. My name featured in the film credits. Happily I was able to have one scene scrapped in which randy ‘Uncle Ranald’ was summoned from the great beyond. Small victories …

The studio set prepared for the film mysteriously went up in flames. There was panic. A wealthy friend of Davis’s, a stockbroker with an interest in film production, was in the United States and agreed that his house - a palatial mansion in Chiswick - could be used if needed as a set. A barn was constructed in the sizeable garden - enormous in fact. The garden was ruined. Something like £30,000 was spent on returning it to its former glory after the shoot. It was churned up into a muddy field, effectively. But it looked good. I visited the set with Crystal. It wasn’t my thing. You can imagine that it was a fast-living crowd and there was a lot of drinking and I daresay consumption of much else besides, not all of it legal. The actress playing Sophie Small was pleasant and charming though I formed the impression that she was a little naive and didn’t know quite what she’d let herself in for. Davis was in a relationship with her. I was told that it was short-lived and ended acrimoniously. In any event, I stayed for five minutes. Crystal said she had deep misgivings about the whole thing. And she was right to be wary, as we later discovered.'