Garth Greenwell and I had connected online before he and his debut novel, What Belongs to You, crossed the Atlantic. He had read my novel and I was excited about his as it was being hailed as a masterpiece by Edmund White and every major outlet in the US seemed to have fallen under its spell. It has received the same ecstatic reception in Britain, with the Daily Telegraph calling it “an essential work of our time”. I got to meet Garth on his brief trip to the UK and on London’s South Bank we talked about writing. This is a lightly edited version of that conversation.

What Belongs to You started off as a novella, which won the Miami University Press Novella Prize.

Yes, it was a publication prize. There are very few places that publish novellas as standalone books. When I wrote Mitko, it was the first piece of fiction I’d ever written; before that I’d only ever written poems. When I finished it, I thought that the story was done, as it tells a complete arc. I thought it was finished but it’s what’s now the first section of What Belongs to You.

Happily, between submitting to the Miami Prize, winning and signing the contract for publication, I realised that Mitko was part of something larger, that there would be more to come, and so I was able to make sure that would be possible with Miami University Press.

Can you pinpoint the moment you realised it was meant to be a longer piece? Was it a wake-up-in-the-middle-of-the-night experience?

I think at every point in writing the book I was completely in the dark about what it was going to be. I feel like it’s a book I wrote not just sentence by sentence but really clause by clause.

After finishing Mitko I didn’t think I was going to write more prose for a while, I thought I had some poems to write. And then one day I just started hearing this very importunate and angry voice. It just took me over. I wrote the second section of the book very fast, in a white heat. And it wasn’t until I was deep into that section that I realised it was connected somehow to Mitko. Even though the character Mitko doesn’t appear anywhere in that second section, I understood that it was the same narrator and that somehow the story that voice was telling was in resonance with the story of Mitko.

You said you wrote What Belongs to You clause by clause, which is how I imagine a poet writes/thinks. Do you think being a poet has helped bring something different to your novel?