It's a chilly, February morning when we meet for coffee and a chat, but the sun is out and author Lucy Clarke is heading off to her "favourite place the world over".

The family beach hut at Hengistbury Head is where Lucy spent much of her childhood, where she met her husband, Jim, and where she now writes her hugely successful novels.

After her first book, The Sea Sisters, was selected for the Richard and Judy Book Club shortly after its publication some six years ago, Lucy's career has continued to climb and she is now celebrating the release of her fifth novel, You Let Me In.

"They're all set by the sea," Lucy smiles, "it was never a conscious decision, but just felt very natural to me, being brought up by the sea and writing by the sea."

The psychological thriller has been selected by Fern Britton's book club, Fern's Picks, and the ebook and hardback, which was released in September, have already sold just shy of 100,000 copies.

You Let Me In is in the same vein as Lucy's previous books, which all have an element of suspense but she admits that, while this one is of a similar genre, it is "probably a little bit darker".

"This one is set in a beautiful cliff top house in Cornwall," she explains. "Often my books are set abroad, but this one is all set in the UK. The writer's room in the novel looks out to the sea. My books are not autobiographical, but they're deeply influenced by the stage I'm at in my life.

Now 37 and a mother-of-two, Lucy was just 30 when she got her first book deal. But she still admits to having "pinch me" moments.

"When I first got published and was getting paid to write I just couldn't believe it," she says, "I was getting paid to write!

"I love writing every day - I love it no less than back then."

With the market currently so saturated with psychological thrillers, Lucy admits being an author is even harder now than when she first started out. But she is determined to stay true to herself.

"I made a decision back in my 20s that will stand throughout my career," she explains. "I'm 100 per cent a writer, whether I'm earning money from it or not. I will always want to write what I'm passionate about, which will not always be a market trend.

"But I made that commitment to writing." You Let Me In is featured in the Time to Unwind gift package by Poppy & Pearl. Retailing at £39, the box includes a signed copy of the book; a box of Moore’s luxury chocolate chip biscuits; a beautifully scented St Eval Bay & Rosemary Candle; an organic vegan Rosewood hand cream; a Rosa dusky pink mug and two types of tea, all encased in an iconic polka dot Emma Bridgewater tin.