In The Baddies, the witch, the troll and the ghost come a cropper when a little girl refuses to be scared by them. Although it’s never mentioned in the story, she is of south Asian heritage. Is this the first time they’ve featured a non-caucasian main character?

I also continued to write “grown-up” songs and perform them in folk clubs and on the radio, and have recently released two CDs of these songs. Funnily enough, I find it harder to write not in verse, though I feel I am now getting the hang of it! My novel THE GIANTS AND THE JONESES is going to be made into a film by the same team who made the Harry Potter movies, and I have written three books of stories about the anarchic PRINCESS MIRROR-BELLE who appears from the mirror and disrupts the life of an otherwise ordinary eight-year-old. I have just finished writing a novel for teenagers. I get a small percentage of the sales price and of course I share that with Axel, or the other illustrators.” Still, compared with other authors, she has clearly made a lot of money. Has she enjoyed spending it? I grew up in a tall Victorian London house with my parents, grandmother, aunt, uncle, younger sister Mary and cat Geoffrey (who was really a prince in disguise. Mary and I would argue about which of us would marry him). Donaldson has in the past talked about her concerns for today’s children, from them having to wear masks in school to the effects of social media. So I persist with my theory that perhaps The Baddies is a parable about how much resilience modern kids need to deal with the world – and she persists in batting it away: “No, no, no,” she says firmly.One thing Donaldson and Scheffler understand after all these years is that kids like to be scared — just not too much. Does she see books as a way for children to learn about the world around them, or an oasis in which they can escape from it?

She wasn’t unhappy, she adds, just sensitive. “I just couldn’t understand other people, and even when I was about 10 I would always have one little cry every day.” One year her father gave her a poetry compilation, A Book of 1,000 Poems, and she decided to become a poet (she cites Shakesapeare as an influence and has recently written a story in iambic pentameter for the first time). He tends to read things out loud in what we call his Dylan Thomas voice, this sort of cod Welsh accent, and it always sounds quite good when he does it.” She always replies to children’s letters. “And they haven’t changed over the decades. It’s always the usual mix of ‘Where do you get your ideas from?’ to ‘Why do you wear such funny shoes?’ I love it, because adults are probably dying to ask about my shoes but they just say, ‘Are you inspired by Tolkien?’” Julia Donaldson and Axel Scheffler started working together more than 30 years ago, on A Squash and a Squeeze. Donaldson had written the story as a song when she was in her 20s — years later she got a call from a publisher who wanted to turn the song into a children's book. She was paired up with Scheffler for the illustrations. Their second book together was The Gruffalo. What I like about Julia's text is the subtlety of her messaging," says Scheffler. The Baddies is about kindness, and how being good is better than being bad at the end of the day. But mostly, it's just supposed to be fun.It should be funny and they shouldn't be too scary," says Axel Scheffler of the three baddies. "They're really ridiculous."

We are experiencing delays with deliveries to many countries, but in most cases local services have now resumed. For more details, please consult the latest information provided by Royal Mail's International Incident Bulletin. The spark happens when when when the pictures come together with the text in the book," explains Scheffler. "We're very different people and it's amazing that it works so well." When a little girl moves into a nearby cottage, the three baddies are practically giddy. They decide to compete to see who can steal the little girl's blue hanky.We have sailed past our allotted time by now but I have one last question from my three-year-old: why, at the end of A Squash and a Squeeze, does the pig look angry but the other animals don’t? Did they instantly know, when Scheffler made the drawings for A Squash and a Squeeze almost 30 years ago, about an old woman who thinks her house is too small, that they’d found each other’s work soulmate? The Smeds and the Smoos wasn’t about Brexit, it was just Romeo and Juliet with a happy ending,” Donaldson insists. “I never start a book thinking, ‘I want to teach the world to stop being at war.’” I really enjoy writing verse, even though it can be fiendishly difficult. I used to memorise poems as a child and it means a lot to me when parents tell me their child can recite one of my books. Scheffler found his way into art by being political. “When I was growing up in Hamburg, there was the Vietnam war going on, the Israeli-Palestinian conflict, and there are teenage drawings of mine in which I reflected on that, so that was my formation,” he says. “Oh! I didn’t know that,” says Donaldson, turning to him in surprise. “Now I draw rabbits and mice,” he says and they look at each other and laugh.

You’ll have to ask the pig, I’m not responsible for my characters!” laughs Scheffler, and Donaldson nods: “It’s nice when children see things in the books I’m not aware of. You know they’re really looking at them.” Donaldson occasionally — but not always — writes in verse. "I was a songwriter," she says. "So I've written... I don't know, 200 songs before I'd ever written a single book." It comes naturally — but she says the verse has to have a structure. In The Baddies, it comes from the same phrase, repeated throughout the story. Malcolm, whom she mentions frequently, is the only person with whom she shares early ideas and drafts, discussing things while walking near their home in West Sussex, and showing him “half-baked manuscripts”. I feel that's part of my job," adds Scheffler. And, as fans of their work know, there's always a picture of a gruffalo hidden somewhere in each of their books. After studying drama and French at university, she busked around Europe, joined by a fellow performing enthusiast, who was, of course, Malcolm. I ask if their busking days inspired Donaldson and Scheffler’s book, Tabby McTat, about a busking cat and his shabby human, Fred. “Julia’s sister says Fred is who I’d be if I hadn’t met Julia, which I deeply resent,” Malcolm chortles. He is certainly as devoted as Fred: when Donaldson can’t remember quite when she finished writing The Baddies, Malcolm consults his diary and gives her precise start and finishing dates.They are the brains behind dozens of picture books including Room on the Broom, Tabby McTat and, of course, The Gruffalo. One of their latest books together is The Baddies — about a witch, a troll and a ghost who like being bad. Frog and Toad, George and Martha, Curious George and the Man in the Yellow Hat: iconic duos abound in children's literature. Another classic pair? Julia Donaldson and Axel Scheffler.