The runaway sales success of her psychological thriller He Said/She Said gave Erin Kelly the security to ‘keep on writing for another few years’.

The book spent six weeks in the top ten in both hardback and paperback, was longlisted for the Theakston's Old Peculiar crime novel of the year award, and selected for both the

Simon Mayo Radio 2 and Richard & Judy Book Clubs.

It  begins with a young couple witnessing what they think is a rape; they report it to the police, but that decision has repercussions on them which no-one could have predicted.

‘I’ve been incredibly moved by the emails I’ve received from victims of similar crimes,’ says Erin Kelly. ‘I’ve never had a reaction like it.’

Kelly has worked for many years as a journalist, writing for publications such as The Guardian, Daily Mail, Sunday Times and Cosmopolitan, but she admits that writing fiction is her first love.

‘I still dip into journalism but my middle-aged brain is more suited to longer projects I can lose myself in than the constant chop and change of freelancing.’

However, she readily admits that journalism has fed into her fiction, ‘but perhaps not in the ways you might expect. I rarely draw my stories from the headlines. What journalism did teach me was research skills – how to read widely and quickly and pick up the details that will make the story come alive for the reader.’

Erin Kelly’s new book, Stone Mothers, is published just a month before the Guernsey Literary Festival, and she will talk about the book --  and her other work -- at 10 am on Saturday 4 May in the Festival Hub in Market Street.. She is also taking part in the Crime Time writers’ conversation  with Mark Billingham at St James on Sunday 5 May at noon. Both events are sponsored by Appleby.

Stone Mothers’ main character is Marianne, who grew up in the shadow of the old asylum, a place that still haunts her dreams. She was seventeen when she fled the town, her family, her boyfriend Jesse and the body they buried.

‘A friend of mine went urban exploring in an abandoned mental hospital and found a cabinet full of confidential patient records,’ says Kelly. ‘I thought, “in the wrong hands, that information is terribly dangerous” – and my story was born.’

Erin Kelly’s previous books include The Poison Tree, The Sick Rose, The Burning Airand The Ties That Bind, and she was also commissioned to write Broadchurch: The Novel, inspired by the mega-hit TV series starring Olivia Coleman and David Tennant.

Good writers read a lot, and Kelly is no exception. ‘Before I was published, I loved Ruth Rendell, Daphne Du Maurier, Nicci French, Maggie O’Farrell, Ian McEwan, and I still love them all,’ she says. ‘Newer writers I really rate include Susie Steiner, Sally Rooney and Megan Abbott. My favourite books combine rattling plots with beautiful sentences and really good psychological insights – I’m greedy, I want it all.’

This will be Erin Kelly’s first visit to Guernsey and she is looking forward to it. ‘I love to walk and I’ve heard the island is a great place to explore on foot.’