Death turned up in the Discworld books in order to make a joke work. That was in The Colour of Magic. Suddenly he was and, twenty-one years later, still is one of the most popular characters in the series. People ask me to forge his signature in books. Sometimes I get nice letters from people who know they’re due to meet him soon, and hope I’ve got him right. Those are the kind of letters that cause me to stare at the wall for some time.