MAGGIE O’Farrell began her ambitious seventh novel in 2013 after the birth of her second daughter. Not, you might be forgiven for thinking, the most auspicious time for a mother of three young children to begin writing a doorstop of a book.

At 486 pages, This Must Be the Place is the Irish-born, award-winning author’s riskiest, longest book. It’s also the novel in which she deliberately “ripped up the rule book”, tossing its pages in the air and catching them where they fell. The result is dazzling, her most accomplished book yet and proof that the pram in the hall is not the “enemy of good art”. (Although we note that the infamous perambulator rarely features in interviews with male authors.)

In any case, O’Farrell confesses, she adores her children. “I feel enormously privileged to be their mother.”

Spanning time zones and zooming between 15 locations, from Donegal to Bolivia (all places O’Farrell, an inveterate traveller even with small children in tow, has visited), the novel is narrated by a compelling cast of characters, ranging from Claudette, a globally-famous film star living hermit-like in Ireland, to Daniel, an American academic, with a convoluted private life, and their various children. It’s a heartbreaking, funny book tapping into O’Farrell’s continuing fascination with dysfunctional families, their secrets and lies.

For ages, O’Farrell confides when we meet in Edinburgh, where she and her husband, writer William Sutcliffe, now live with son, Saul (12), and daughters, Iris (7) and Juno (3), she had wanted to write a novel about a recluse, someone who exits her life and fakes her own death. “But I couldn’t find a way to make the story fit, it felt flimsy,” she said.

Then, some seven years ago, new-baby weary and desperate for a cup of tea, she went into a London cafe, with Iris. “The room felt strange, there was an odd atmosphere. Then I realised that sitting opposite me at this trestle table was an incredibly famous actress – anyone anywhere in the world would know who she was. Everyone in the room was staring.”

Do tell, who was she?

“No, I am not going to name her because this is a story about privacy. She was looking really miserable, slumped, with her head in her hands. If she hadn’t been who she was I would have said, ‘Are you OK? Do you need anything?’ But you can’t say that to somebody that famous.

“When I went to the loo, I found I was in her slipstream. Everyone was looking at her, telling their friends, taking photographs. I got a whiff of what it must be like to be her. I felt this wave of horror, the essence of the misery it must be to be looked at all the time. In the loo she was leaning against the mirror, head pressed against it, eyes closed, trying to gather herself. Again, I wanted to say, ‘Is there something I can do?’

“But I couldn’t; I thought how miserable her life must be even though she is probably one of the richest and most successful women alive. I remember leaving the cafe and thinking I could now write that novel about a recluse, a woman like her who finds a loophole and disappears.”

THE idea “bubbled away”. Meanwhile, O’Farrell wrote the bestselling Instructions For a Heatwave (2013), a novel with strict technical boundaries, told over four days in four different voices. “There was a unity to it because I’d set myself a challenge. When I finished it, I wanted to break out, to do something experimental – for instance, there are pages in the new book from an auction catalogue of memorabilia relating to Claudette, with my own photographs, that I really fought to keep in.

“I wanted this novel to have a lot of energy but still couldn’t find a way in. One day, driving the kids to school through the rain I heard a 1980s’ radio interview with a woman. Afterwards, the announcer said she had died shortly afterwards. I thought how shocking that would be if you didn’t know. By the time I got home, I had the opening scene of This Must Be the Place. I sat down and wrote it, because I knew how Claudette and Daniel’s stories could come together.”

Educated at Cambridge University, where she met her husband, O’Farrell is a former arts journalist and deputy literary editor, which explains why she can type “very, very quickly” when she escapes to her desk. The results have had literary critics reaching for superlatives for six richly-imagined novels, such as The Vanishing Act of Esme Lennox and The Hand That First Held Mine, although she never reads reviews despite glowing comparisons with Rebecca West and Daphne du Maurier.

“I think This Must Be the Place makes demands on the reader,” she admits. “I love books that don’t hand you everything on a plate.”