I f you ever find yourself in an airport newsagent, it might be worth peering inside one of Liz Pichon’s books. “I do guerrilla signings,” she tells me conspiratorially. “They let me go in and I sign all the books, just in case. I love the idea of kids buying a book, going on holiday and seeing that I’ve signed it. Sometimes I write ‘surprise!’”

It’s a wonder that she hasn’t got sore hands. Pichon is one of the UK’s foremost children’s authors, and this is a big year for her. Not only has she just published the 25th book in her Tom Gates series, Tom Gates Is Not Famous (Yet), but this is the 15th anniversary of the first instalment. She has, at last count, sold 16.5m books in 47 languages, and her work has been adapted for both stage and screen.

Illustration: Liz Pichon

“I can’t believe it’s 15 years since the first one came out,” she says on a video call from her home. “Now I get 19- and 20-year-olds that grew up with my books.…