As the daughter and granddaughter of a newspaper editor, Marika Cobbold is well placed to write about a jaded local journalist squeezed by fake news and social media clickbait.

Until recently her family owned a paper in Gothenburg Sweden that was founded by her grandfather and modelled on the great Manchester Guardian: "A big circulation local paper that acted as a national broadsheet".

"It's been dreadfully difficult because of the digital revolution," she says. "Advertising revenue is down, the MD made some stupid decisions, and the Swedish government landed all the newspapers with back tax so we lost the newspaper."

When the Hampstead author was thinking of an anti-heroine for her eighth novel, Thorn Marsh emerged as a workaholic news editor who falls foul of the media giant that has bought The London Journal. Living in Hampstead's ugliest and therefore most affordable house, Thorn "as in your side" values integrity, pursuing the truth and holding the powerful to account, while they value clicks over fact checking.

When Thorn spikes an irresponsible anti-vax story, she's demoted to write upbeat articles for good news edition 'The Bright Side'. "Her idea of hell". So she drunkenly makes up something sensational. Based on a photograph of a man jumping from Hampstead Heath's Viaduct pond, Thorn's invented story about an angelic vision of a daring rescue goes viral and the lies snowball.

Ham & High: The Kenwood Viaduct Pond where Marika sets a crucial scene of her novelThe Kenwood Viaduct Pond where Marika sets a crucial scene of her novel (Image: Ken Mears)

"The big theme I was playing around with was the idea that somebody whose life was a complete mess and who had no belief in themselves wakes up in hospital and everyone thinks they have done something amazing," says Cobbold who has Thorn chase down the amnesiac angel to a hospital bed.

"If this hero suffering from temporary memory loss believes the lie, how does that change his life? And then the person who instigated the lie sees it has an impact on other people. What if the lie becomes something that's good? How do you deal with the consequences, do you disillusion everyone?"

While On Hampstead Heath casts a witheringly satirical eye over the death of newspapers as guardians of democracy and erosion of trust in the "much hated mainstream media," it's as much about finding unexpected love and exorcising family secrets, as it is about "Trump, Brexit and alternative facts".

"The love story which in her case is not based on reality but becomes something more real is part of the whole mirroring of truth, lies and perception."

But through Thorn's elderly Jewish neighbour Lottie, Cobbold points to the consequences of conspiracy theories and lies.

"Alternative news stories scare the s**t out of me," says Cobbold. "Some are downright lies and if people believe lies how can you have a functional democracy? The further away we get from the source of information the less accountability there is."

For Cobbold the pandemic "has been ok" even though she struggled to write.

"I have been lucky. I have a nice life. I have a husband and have been able to bubble with my daughter over the road," she said.

"But lockdown doesn't do a lot for creativity. If you had asked me in 2019 whether I wanted a break from the world so I could get on and write without people popping by or being invited to something I don't want to go to, I would have said yes. But then it happens and I couldn't focus on anything. You are aware all the time of terrible suffering, people dying and losing their jobs, and the strange disconnect with others saying 'this isn't so bad let's bake banana bread.' There was that sense of waiting..for statistics, the next change in rules, of not quite knowing what was going on. My concentration was shot to pieces."

Ham & High: Marika Cobbold's eighth novel is published by Arcadia Books £14.99.Marika Cobbold's eighth novel is published by Arcadia Books £14.99. (Image: Arcadia Books)

On Hampstead Heath is published by Arcadia Books price £14.99.