And since it’s Terry Pratchett, it also has fart jokes and terrible puns. There are no easy answers, no quick-fix heroics and nothing goes the way it’s “supposed to”. What follows, however, is far more than an adventure story about talking animals – it’s a treatise on the nature of the self and the power of narrative, with a sombre genocidal subplot.

The whole ensemble of rats, cat and kid then heads to the next town to pull the scam again. It begins as a parody of the old Pied Piper folk tale: a talking cat (the titular Maurice) persuades a group of similarly intelligent rats into causing nuisance in a town until its people decide they need a pied piper to clear them away – at which point a handy “stupid-looking kid” with a flute appears, takes their money and enchants the rats to leave. The Amazing Maurice is one of the finest stories in Pratchett’s canon – and an accessible one for the uninitiated, as it’s a standalone adventure. The Amazing Maurice and His Educated Rodents was a turning point in Pratchett’s career, bringing about a seachange in his critical and literary acceptance. Though it wasn't unusual for Pratchett to return to asides in previous books and spin whole plots and themes out of them, this was different. The germ of the idea clearly had been in Pratchett’s mind for a while: it’s mentioned as an aside in his 1991 novel Reaper Man. “I’d not been working with him that long, and it was the first time I’d really seen him write like that – just have the whole thing download straight out of his head.” Two decades on, and with a new Sky screen adaptation of The Amazing Maurice now in cinemas, Wilkins, who has a puppyish energy of his own, recalls his awe at the speed his boss’s mind could work at. Eighteen months later, it won the Carnegie. We started writing it that night, with him dictating it and me rattling it off on a laptop. It was a scam’, and he started telling me the story of the Amazing Maurice. “I asked him what he meant and he said ‘The Pied Piper.

“We were in the Pied Piper Bar, drinking local beer, looking at the painting they have, and he suddenly said ‘You know it was all just a scam, don’t you?’.

“It happened at the Palace Hotel in San Francisco,” recalls Rob Wilkins, one-time PA of the late Terry Pratchett and now the executor of his literary estate.

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