Yes, I’ve previously cowritten two books on academic writing for students with a colleague when I was teaching at the University of Birmingham. They’re about structure, language, editing, style—all relevant to fiction too, of course; I was always noticing the overlaps. One of the books also deals with how to use feedback from others to improve your academic writing—something I can wholeheartedly say is also essential to novel writing! I had no coauthor for support when I wrote The Downstairs Neighbor—that was one difference—but I did have my agent, my writers’ group, and later my editors to give me lots of much-needed feedback and encouragement.

Fiction was my first love: I’ve been writing stories and books since I was young (not necessarily finishing them!). I wrote most of The Downstairs Neighbor on my daily commute to work at the university. Fiction is exciting because you can go anywhere with it; you can step into different worlds and different characters’ heads. But it’s also more challenging, because you have to achieve so many things at once—intrigue, empathy, believability, emotion, surprise! A novel is a sprawling, overwhelming thing while you’re writing it, but there’s nothing more absorbing and rewarding, in my experience so far. Deciding what story to tell, and how you want to tell it, is a joy.

What inspired you to tell this particular story?

I love psychological suspense novels, particularly ones that pack an emotional punch. I wanted to write a book that was twisty and a bit dark, but that also revolved around families and relationships.

The first seed of an idea was the image of a neighbor in a shared building, overhearing something shocking. Everybody hears or sees fragments of their neighbors’ lives sometimes—but what if those glimpses were disturbing or worrying, or what if you became obsessed with piecing them together? I’d also been thinking about the secret histories that can exist within a family—parents’ lives before they were parents, or spouses’ before they were married. How they might feel like they were different people in their pasts.

Weaving in other ideas that had been floating around my head (for example, the character of a driving instructor who teaches lots of teenagers in the same neighborhood), I started building this story about people living close to each other, all with something to hide from those around them.

All of the voices in the novel feel so unique—where did these characters, and their voices, come from? Which came first—the characters or the plot?