Melvin Burgess, 68, was born in Twickenham and lives in Todmorden, west Yorkshire. The author of more than 20 novels for teenagers and children, he won the Carnegie medal in 1996 for Junk, in which two 14-year-old runaways fall into heroin addiction; Malorie Blackman, introducing the book’s 20th anniversary edition, said it “opened my eyes to the possibilities when writing for young adults”. When Anne Fine reviewed Burgess’s 2003 novel Doing It for the Guardian – it’s about the sex lives of three secondary school boys – she said the publishers should be “deeply ashamed”, advising them to “leave this age group… to find that sort of filth for themselves”. Burgess’s new novel, Loki, a retelling of Norse myth, is his first book for adults. Why did you write Loki? There’s a lot of lying bastards about, politically, and Loki – the trickster god, the “father of lies” – seemed a way to explore the nature of lying and the nature of being convinced. I’ve always been keen on mythology since I was small. My dad worked for Oxford University Press and he used to bring me back their books on myths and legends. I liked the Norse myths best. The modern retellings by Kevin Crossley-Holland and Neil Gaiman are written in a kind of folk-tale third person, which is fine, but it’s quite distanced; I wanted to make the stories more immediate, like the Greek books of Madeline Miller and Pat Barker, which I enjoyed enormously. Loki was always my favourite god – I’m attracted to baddies – so in lockdown I decided to try and tell the myths from his point of view as a kind of experiment. The voice that emerged was very scatological, very untrustworthy, and I just let it take over. What led you to try writing in Loki’s voice? A friend in Leeds, Martin Riley, has a theatre company, Alive and Kicking, which does events for kids. They’ll go into a primary school that’s doing the Vikings, say, and he’ll be the protector god Heimdall, who’s lost his courage. The kids have to give it back to him; if they fail, the frost giants take over Asgard [the gods’ home]. Martin said: “Why don’t you come along and play Loki and try to beat me by getting the kids not to give me back my courage?” We did it for a few years and it was a lot of fun. He kept saying I should do a book. I was planning to write it with a poet friend who was going to do Loki’s voice but I thought, actually, that’s the best bit, why give it away? The Loki you played must have been very different from the Loki you’ve written… There was no horse-fucking, I can promise you! It was all very decent but the Norse myths are full of violence and there’s quite a lot of sex too, so I ran with that in the book because it was true, mythologically speaking. Any collection of Norse myths will tell you the gods did a deal to build a wall to keep the giants out of Asgard. They were going to lose the sun and the moon and the beautiful goddess Freyja [to pay the builder for getting it done in a year]. So Loki turns himself into a mare and leads the [builder’s] stallion away [to slow things down to avoid paying]. He fucks a horse and produces a foal; even though I’m known in the YA area for transgressive things, I don’t think I’d have bothered putting that in a YA novel. So Loki was always going to be a book for adults? There was no question of it being something I was aiming at young people. When you write for young people, it’s not that you’re censoring yourself, it’s that you’re writing about being that age. Loki isn’t about being that age; there isn’t anyone of that age in it. I’ve made a career out of remembering being a teenager and trying to relate to that time, but it was bloody long ago! I don’t really have much more to say about it. Adult stuff is where I’m looking now. I’ve got more Norse gods bubbling away – I want to get grips with Odin at some point – as well as a long-term project around the childhood of Bill Sikes [from Oliver Twist]. What do you make of young adult fiction’s emergence as a genre? When I started writing in about 1990, publishers were very keen on the teenage market. They knew kids were spending money on music and that there were films for kids that age, but books somehow weren’t quite happening. The fuss when Junk came out was because it really was a book for teenagers. If you’re 14 or 15 or 16, of course you’re thinking about sex and drugs and rock’n’roll, but there was a gap in what kids wanted to read and what was being produced for them; it was all right to pinch stuff surreptitiously from the adult world, but no adult was allowed to present it to you. That gap was one of the things Junk helped bridge. Before then, a book for teenagers would really be more suitable for someone aged about 11. There’s much more honesty now – books are tackling difficult issues in a realistic way. What did you and your peers read in your teens? I failed my 11-plus and there weren’t all that many books being passed around at my school, stuff like In Praise of Older Women [by Stephen Vizinczey], just dirty novels really! George Orwell interested me because of the clarity of his vision and the simplicity of his writing but at that point I really liked fantasy and I was very keen on Mervyn Peake and Gormenghast. It wasn’t until I left school and started coming across a richer world of ideas, when books like The Dice Man, Catch-22 and Slaughterhouse-Five came shining through, that I began to think there might be a way of telling stories connected with life itself. Which books have you enjoyed lately? At the back of Loki there’s a painting by the writer and artist Brian Catling, who died recently. I’ve been reading The Vorrh, his fantasy trilogy about a semi-aware dark forest in Africa, which is fascinating on how to think about fantasy’s relationship with the real world. And I keep returning to Japanese fiction like Breasts and Eggs [by Mieko Kawakami] and Convenience Store Woman [by Sayaka Murata], which I love. The end is really wonderful, when the main character is told: “You’re not human!” and she thinks: “That’s what I’ve been trying to tell you!” Reading western stuff, you quite often just kind of know what’s going to happen; you think, this is great, but I’ve read it before. When something a bit different comes along, I’m profoundly grateful. Loki is published by Coronet (£16.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply