Samantha Harvey weaves a dazzling tapestry around loss and confession in late-15th-century England in her breathtaking novel The Western Wind. Thomas Newman, benevolent landlord and relative newcomer to the hamlet of Oakham, disappeared into the river on the Saturday before Ash Wednesday. Parish priest John Reve recounts the icy unnamed rural dean’s condescending investigation into the death across four days in reverse order, beginning on Shrove Tuesday, the day Newman’s shirt is found near the river. Harvey examines how she solved several historical issues that presented themselves during the writing of the novel.

Probably everybody in the world knows that in the 1400s, Catholic churches did not have private confession boxes. It’s one of those things that everyone but me is just born knowing—that until well into the 1500s, the penitent knelt at the priest’s feet in the nave for all to see and hear. Of course. But because I didn’t know it, I embarked on writing a novel set in 1491 which centered on an English parish priest taking confession, in his confession box, over the four days of Shrovetide.

Two hours of research set me straight, but left me in at a loss. I needed there to be a confession box in my novel—the novel rested on it. I couldn’t shift the period forward to the 1500s because it needed to be pre-Reformation, and I’d arrived at 1491 as a calibration of all sorts of other details—just as Renaissance thinking was beginning to permeate English culture, just before a priest’s usefulness was to be challenged by the translation of the Bible into Modern English, the invention of the printing press, and the challenge of Protestantism, just before the discovery of America.

Yet, how could I dismiss this fact? I’m a novelist and a lover of fabrication, but I don’t believe overly in reinventing facts, not only because there will always be someone who catches you out, but because, well, why bother? It seems to defeat the purpose of writing about a particular subject if you want to evade the truth of that subject.

Truth—there’s a word. I’ll come to it, tentatively, in a moment. But I want to speak about what I did to resolve this problem of the confession box, because it seems to me that it reveals something about the strange dance between fact and fiction that we call research. Research is a dance; if it sounds airless or rigid then be assured it’s the opposite: dynamic, expansive and enlivening. And, though I hadn’t written historically before, I’d written novels that depended heavily on research, and always found this same interdependence of facts and the imagination, and their mutual thriving off each other.

I decided that I could keep the confession box in my novel if I could acknowledge and explain how it was that a small, inconsequential village called Oakham—itself made up—could be the first in England to have such a thing. What conditions could make it possible, and what social, cultural, psychological, religious detail could make it plausible? In terms of novel writing, plausibility seems to me the more interesting cousin of truth. It’s where facts are arranged in such a way that they align to form a feeling of truth—a truthiness—that infuses the novel and becomes part of its internal logic.

In my case, this came down to the character of the priest, John Reve. The confession box had to be his doing, since it would be in his church. Why would he want it? What did he have to gain by having it? What resources did he have to build it? Who did he have to convince? What did he have to lose? What forces were at work for and against him? In answering each of these questions I developed a distinct sense of the man he was, one that suddenly illuminated other elements of the novel and of the time. I knew, for example, that in early 1491 Robert Stillington, the Bishop who would have served Oakham (had Oakham existed), was dying in prison—a fact that now came into play as part of the rationalization for the confession box. The rationalization also made sense of new facts. I found, if you like, the novel’s themes. I located its beating heart.

Writing is a form of spellbinding. Anything amiss will break the spell—anything that seems wrong or off-key or untrue or disingenuous or, ironically if fiction, made up. (Of course, fiction is making-up by and large, but the trick is to make it seem not so at least while the reader is reading.) The spell is cast when there is a feeling of truth about what’s happening—whether that’s come about by adhering closely to facts, or by subverting, manipulating and coloring the facts. To me this isn’t a moral question about fiction’s responsibility to the truth, as some would have it, but only an aesthetic question. You do whatever you need to do to sustain the spell.

This isn’t to say that there’s no place for simply abiding by facts, not getting things wrong. Most of the time, not getting things wrong is the aim. Having bestrewn my novel with pockets, for example, I discovered that the clothes of European medieval men and women didn’t have them. No pockets? Where did they put their things? Where did they put their cold hands? How could it be that these people could build splendid cathedrals, yet hadn’t thought to make a pocket? Still, I removed them all. I relocated coins, trinkets, rosaries, bobbins, nails, pliers to purses or burses or boxes or hands.

Yet sometimes you have to get things wrong to get them to feel right. Writing historically has felt to me more like an act of translation in this sense; sometimes the word-for-word translation won’t do. You are translating concepts in a way that gives them life in the present, or more literally translating from a lost or seldom-used language, as I had to from Middle English. A simple example—just as medieval people didn’t have pockets, nor did they have trousers (pants). A discussion about 15th century legwear with my medieval scholar friend clarified that "hose" would be the accurate word—hose were baggy woolen stockings that didn’t meet at the crotch, or tights that did. To his exasperation, in the novel’s first chapter the word trousers nevertheless appears.

My problem here was that "hose" has a particular ring to it, in British English at least, either of something antiquated, or of women’s lingerie. (Though, as an aside, I’m aware of the fact that "trousers" itself sounds old-fashioned to an American ear, so there are two layers of translation at work here.) It wasn’t a word that sat well in my novel. I wanted to bring freshness, vitality to the world I’d made, just as it was fresh and vital to itself. We all live on the brink of the next moment, we are all in our own now. This is how Mantel captures her Cromwell, and Rose Tremain her Merivel—they are alive in their own present. They are thoroughly modern men.

If you include words that are true to the time but dusty and antiquated now, you risk a novel that is accurate but half-dead. A man in hose in chapter one is a man in an historical novel. He isn’t a modern man. But to himself, he is a modern man, in his own present—and that is the greater truth. There’s something anomalous here, that in order to be truthful about your subject you’re sometimes driven to be inaccurate. When I read wonderful historical fiction I know it will have been meticulously researched, but I don’t care in the end which things were true and which things invented; they were all alive, they all spoke for their time.

For myself, the process of inventing the context for a confession box was perhaps the single biggest catalyst for the novel’s direction, shape, characters, drive and mode of telling (which is backwards). The invention born of this necessity was what rapidly evolved the novel and made it what it is. Paradoxically, this act of invention was what set the novel more firmly and factually in the context of its own time.

Besides, having reasoned the confession box into being, I now like to think that the invention might itself, inadvertently, be a fact. I like to imagine that somewhere in 15th century England was a church with an enterprising priest and a cheap, makeshift confession box in its south-west corner - the fact recorded in church records hidden somewhere, crumbling, barely legible, and waiting to be discovered.