Written over a four-year period on 15-minute bus journeys to and from work in Dundee, Chris Carse Wilson’s ambitious and haunting debut novel Fray was never intended to see the light of day. ‘I genuinely had no intention of publishing it. In fact, it’s beyond that: I had no intention of ever showing it to anyone, full stop,’ admits the author. ‘My wife didn’t even know about the book until I finished the first draft. I wrote it because I needed to do it for myself.’

Fray follows a nameless narrator hunting for their lost father in the Highlands. The search leads to an abandoned cottage full of jumbled notes revealing the father’s mental disintegration. Consumed by trying to discover what has happened, the narrator too begins to struggle with reality.

Carse Wilson compares the discipline of writing to running, of which he’s a passionate advocate: he credits both as integral to his mental wellbeing. That love of running sparked the genesis of Fray in 2016, when he was caught on a route halfway up a mountain in Glencoe. ‘This storm came in, and that moment of feeling very powerless, very small against the landscape, kind of unlocked something about how to discuss mental health.’ At the same time, he let go of how he thought he should write and decided to follow ‘what really sets my heart alight.’

Just as he finished the novel, he also had to deal with the impact of an autism diagnosis, after watching a documentary on the subject by wildlife expert Chris Packham. ‘It genuinely was a light-bulb moment of “ok, this feels horribly familiar.” The way he’s talking about extreme anxiety, the way he’s talking about problems in social situations, fundamentally the way his brain works; it felt like he was describing how I feel.’

Carse Wilson has taken this new understanding and turned once more to the power of words. He’s nearly completed the first draft of his second novel (‘the characters have names this time,’ he laughs) which looks at how generations of one family are touched by autism over a century: ‘I want to use fiction to look at how little we understand about it.’

He’s also looking forward to his upcoming appearance at Wigtown Book Festival and is thrilled by Fray’s reception. ‘Obviously to reach an audience is glorious, but I do think there’s an appetite for brave, risk-taking writing. Look at Max Porter and other people like Jenni Fagan with Hex . . . books that are just so brilliantly and uniquely themselves. I think people want that. I don’t think people want more of the same.’

Chris Carse Wilson appears at Wigtown Book Festival, Friday 29 September; Fray is out now published by HarperNorth.