Twenty years ago I was browsing at a charity book stall when I came across a book called The Way to Live by a once-famous and hugely successful wrestler, George Hackenschmidt. He was The Lion of Russia, champion of the world, the greatest wrestler the world had ever seen. The book records his travels, his wrestling bouts, his great achievements. It's filled with photos of him posing, his reflections on life and the pursuit of fitness and strength, detailed measurements of his body. I read the book with delight: it's pompous, fascinating, hilarious and strangely moving. It stayed on my bookshelves from the day I bought it. I wouldn't easily forget Mr Hackenschmidt.

Ten years later, I went to a circus for the first time since I was a child. It was a tattered, run-down thing. The trapeze girl had holes in her tights and during the interval she put a raincoat on and sold chocolate and ice creams from a tray balanced at her waist. There was a little troupe of dancing dogs, and a pair of sad-looking and ineffective clowns. The whole thing was sad, poignant, very beautiful. I remember the smell of the canvas tent, the dusty earth, the candy floss. I remember the way the tent shone at the middle of the dark field that surrounded it. The final act of the show came when a handful of animals — a buffalo, a camel, a llama, a zebra and a donkey — simply trotted round and round the ring. Then the show was over. The whole thing entranced me. Here was something with its roots stretching back many hundreds of years, to a time when a circus must have seemed truly a magical amazing thing, the animals inside it like something from Mars. There was something ancient and wild still existing within it. Next day, of course, the circus was gone, just a ring of beaten grass to show where it had been. The first time I tried to write about the experience I used it in a short story called "Buffalo Camel Llama Zebra Ass."

For years, I taught children with special needs — kids who had problems with language: not only how to read and write, but how to articulate meaning, and make sense to those around them. It struck me how their difficulties were so similar to the difficulties a writer has when he/she begins to put pen to paper or type a keyboard key: how do we get words to say what we want to mean? I had a number of shots at writing about inarticulate kids whose great desire was to create. As I got closer to beginning Secret Heart, it became clear to me that an inarticulate child was to be at the centre of it. His name would be Joe Maloney and he would have an intense desire to create.

I have an Anglo-Indian friend who had many tales of her childhood in India. The story that stayed with me was the one about the man lying in a tent when a tiger came in. He did not dare to move or breathe. The tiger came to him. It didn't attack him, but simply licked the flesh of his forearm that dangled from the side of his bed. The lick took his skin and flesh away. The tiger left, the man breathed and howled silently in agony and fright.

I'm obsessed by the landscapes of post-industrial north-eastern England, particularly the few square miles around where I grew up: abandoned coal mines, disused railways, ancient stone cottages, pony paddocks, newt ponds, new housing developments, turfed-over pitheads. It's all being cleaned up, landscaped, tamed now, of course, but the blend of the ancient and the new and the derelict, the reminders of the past and the yearnings for the future can never be totally swept away. When I began Secret Heart, I set it on the western edge of the town of Gateshead, where there's a slope down through paddocks and old mine workings and an ancient (and once very important) mineral railway to a motorway, after which the land rises again and sweeps upwards towards distant empty moorland. The landscape of the book, with names like The Lostleg Railway, The Black Bone Crags, The Silver Forest, might seem to be some kind of mythical place, but it's just a heightened version a very real and specific part of the world.

The year before I began the book I was in Madison, Wisconsin — again browsing at a book stall. I picked up a book about shamanism, and was immediately struck by how the shaman with his/her wild dance, the entry into the wilderness, the return to civilization, the redemptive purpose, matched the shape of so many of the world's stories, and how the inarticulate child (like Joe Maloney) didn't just connect with the writer, but also with the shaman. Soon, when I began to write the book, it became clear that Joe was a kind of shaman-figure living not in the great wildernesses of North America or Siberia, but in a tatty little town called Helmouth.

In the book, all of these strands, and my many others, came together. I set off several times to write it, but couldn't get it to work. Then the tiger started prowling in my mind. It was when I let the tiger out onto the paper, when it entered Joe Maloney's dreams, that the story came to life. Pretty soon, Joe was out in Helmouth, meeting up with a trapeze girl called Corinna, a mighty wrestler called Hackenschmidt, and performing a shamanic dance in front of his skeptical friend, Stanny Mole.