For all his facility with humour, Freestone says she has been touched by how profoundly Adams’s work has connected with some readers. “In Hitchhiker, all you have to do to be safe is have your towel with you,” she explains. “I heard about this woman who was dying in a hospice who felt she would be fine because she had her towel with her. She had taken Douglas’s universe and incorporated it into her own. It embarrassed the hell out of Douglas when he heard about it. But for her it was literally a symbol of safety when embarking on an unknown journey.”

There are serious themes within his work. The second Dirk Gently novel can easily be read as being about people who are homeless, displaced, and alienated from society. “His imagination goes much deeper than just cleverness,” says Freestone. “The social criticism is usually buried by the comedy, but it’s there if you want to find it.”

Having been through such a lean period, Adams worked constantly until the mid-nineties, when he very deliberately applied the brakes. “I had got absolutely stuck in the middle of a novel, and although it sounds ungrateful, having to do huge book signings would drive me to angry depressions.”

He says that he still thought of himself as a scriptwriter and only inadvertently found himself as a novelist. “It sounds absurd, but a bit of me felt cheated and it also felt as if I had cheated. And then there is the money cycle. You’re paid a lot and you’re not happy, so the first thing you do is buy stuff that you don’t want or need—for which you need more money.”

His financial affairs got into a mess in the 1980s, he says. He won’t discuss the details, but says that the knock-on effect was considerable, so that everyone assumed he was wealthier than he actually was. It is possible to track the movement of Adams’s life even between the first and second series of the radio show. In the first there were a lot of jokes about pubs and being without any money. The second had more jokes about expensive restaurants and accountants.

“I felt like a mouse in a wheel,” he says. “There was no pleasure coming into the cycle at any point. When you write your first book aged twenty-five or so, you have twenty-five years of experience, albeit much of it juvenile experience. The second book comes after an extra year sitting in bookshops. Pretty soon you begin to run on empty.”

His response to running out of fuel was to attempt some “creative crop rotation.” In particular, his interest in technology took off, as did a burgeoning passion for environmental issues. In 1990 he wrote Last Chance to See. “As is the way of these things, it was my least successful book, but is still the thing I am most proud of.”