WHEN you look at the cover of Brooke Magnanti’s debut thriller, The Turning Tide, you may not – as the author herself points out – even be aware that much of the action is based in Scotland, where she has lived for several years. The rest takes place south of the border, where she studied for her PhD and later blogged about her experiences as a call girl under the pseudonym Belle De Jour. Magnanti is now a columnist, author and commentator, best known for her pseudonymously-published Secret Diary of a Call Girl books that were the inspiration for the popular ITV drama starring Billy Piper.

Over coffee in the Merchant City, Magnanti, who is in her early 40s, is witty, sharp and fizzing with ideas. Due to a mix-up before my arrival, we only have a short time together, which is a shame. She’s a pleasure to talk to and she’s clearly had a ball turning to this new genre.

While some may expect The Turning Tide to deal with issues of sexuality, it cleverly avoids obvious connections to the author’s history. “As the story developed, there wasn’t really room for sex! But the thing that related more to my experiences as Belle was, what it’s like when you wake up one morning and the media are interested in you? And you’re just at home thinking: ‘Oh God, what do I do, now?’”

Her novel focuses on Erykah MacDonald, an ordinary woman who becomes embroiled at the centre of a twisted conspiracy that starts with a body found off the shores of a Hebridean island and stretches all the way to Westminster. Encompassing environmental concerns, political ambition and personal responsibility, it also embraces the strong emotions evoked by the independence referendum. Indeed, part of the plot involves a new pro-Unionist political party whose motivations are more Machiavellian than they first appear.

Magnanti has lived in the UK since 1999, but the referendum was the first time she could vote as a citizen. The “sheer symbolic act” of being able to mark the ballot paper was exciting. “I had to be there.” Her husband, she adds, voted No, and she says she understands why he and many others did. She is thoughtful, respectful and clearly passionate about politics, democracy and the opportunities presented by participation in these.

But she also acknowledges that conflict and high passion can arise on either side of any debate. She points to her final opinion piece for the Daily Telegraph. Magnanti was one of the few people at the paper who was pro-independence and, in the latter days of campaigning, she was intrigued by the online abuse that Andy Murray took in the days following his announcement of that he would vote Yes. Her response wasn’t typical of the paper’s stance at the time. “I think they just let me write it to wind up the faithful.”

The article was not concerned with politics so much as online trolling. So it is perhaps ironic that the vehement reactions to it were part of what made her decide to take a step back from commentating. She’s pragmatic about the experience, however, acknowledging that when it came to unsavoury behaviour “both sides were as bad as the other”. She clarifies that these kind of experiences aren’t unique and will likely be had “with any political question,” adding: “Nobody is the innocent side.”

The conversation returns to the idea of the media invading private lives. Near the start of The Turning Tide, Erykah is thrust into the spotlight when her husband buys a winning ticket on a newly established lottery that turns out be a scam designed to raise funds for a shady political party. But Erykah’s already had 15 minutes of fame she’d rather forget, as the girlfriend of a notorious drug dealer. She’s fought hard to get past it, but this new publicity re-opens her old indiscretions to the world.

Magnanti says she relished the idea of writing about someone who made very different decisions from herself. Unlike her, for example, Erykah doesn’t think: “Right, I’m just gonna brazen this out!” Magnanti was aware that the press were looking for evidence that connected her to the Belle De Jour blog, and wrestled with what to do. “Do I run from this or stand up to it? I decided to stand up, because once you start running you’ll be running forever.”

But while it has some parallels with Magnanti’s own life, The Turning Tide is not autobiographical. Like the best crime novels, it uses genre to talk about wider political issues.

“Years after my books have been out, after the series was off television, people still come up to me and say: ‘I think differently about sex workers because of Secret Diary of a Call Girl’. That is extraordinary, that it made people think about these issues in a different way.”