Writing fiction is the hardest, the most frustrating, the most rewarding, the most exhilarating work I’ve ever done, or can imagine doing. Rationally speaking, what I do is make up stories, but it feels like discovery—as if the story already exists, and my task is to divine the shape of it. As if I were a dog following a scent through a dark forest, blundering into trees and losing the trail, casting blindly around until I find it again.

I’d been writing fiction for years—decades—but nothing that really satisfied me, until I stumbled on the idea for The Ghost Writer, a novel built around a series of Victorian ghost stories supposedly written by woman in the 1890s. I still vividly recall being halfway through “The Gift of Flight,” a story set in the old reading room of the British Museum in 1899. Julia, my character, was sitting at a desk on a freezing February morning, and looked up to find herself surrounded by dense fog. I knew that something sinister was going to emerge from that fog, but I had no more idea than Julia of what to expect. When I saw what it was, the hair on the back of my neck stood up.

These are the moments that make all the false starts and dead ends, all the gnashing of teeth over intractable sentences, worthwhile—when a story takes on a life of its own, independent of my plans for it. Tregannon House, the labyrinthine asylum at the heart of my latest book, began as a chaotic litter of maps and sketches and floor plans, but when I finally had it all straight in my mind, the place seemed to materialize above those fragments—a house remembered rather than something invented.

In the early stages of a new book, there’s often a moment when the whole thing seems to unfold before me in full cinematic vision and I think, “All I have to do now is write it down.” But when I get to my desk there’s nothing there, because novels, sadly, aren’t made out of vivid cinematic images but out of words, one after another, like footsteps. Still, there’s immense satisfaction in getting a plain descriptive passage absolutely right, the scene safely on the page. And even if the finished book doesn’t quite capture that first, tantalizingly elusive vision, there’s always next time...