Mark hopes readers will be shouting at the baddies in his latest book

Imagining all of the things that would annoy someone with unwanted guests in their home helped him to write the plot for Here To Stay.

And Mark, who lives in Wolverhampton, promises that readers will be gripped and shocked by how a seemingly ordinary situation can quickly unravel.

"Here To Stay is about a science teacher, Elliot, who lives alone in this beautiful house in London with his cat. He meets this woman called Gemma at an open garden event.

"They have a whirlwind romance after she saves his life after he's stung by a bee and has an allergic reaction and they get married.

"After they get back from honeymoon she asks if her parents and sister can stay with them just for a couple of weeks.

"He's keen to make her happy and her parents Jeff and Lizzy, and sister Chloe move in but Jeff and Lizzy turn out to be in-laws from hell.

"He can't get rid of them and he's driven to his wits end and has to do something about it.

"He's also convinced they've got a dark secret," explains the 48-year-old.

Mark says the plot certainly wasn't inspired by any real-life experiences but a story he had heard about another couple in a similar situation.

"My in-laws live in Penn and as soon as I came up with the idea for this book, I knew I had to tell them what I was going to write about as I knew people would ask if it was based in my in-laws.

"My mother-in-law Julie was actually the first person to purchase one of my books and has always been very supportive. Apart from my wife, she's the first person to read my books.

"It was inspired by a story I heard about a couple who got married. This guy still lived with his parents and he moved his wife into the family home.

"Within two months she had moved out and they'd had a divorce. Her in-laws had treated her so badly, she couldn't believe it and her new husband didn't stick up for her.

"I thought about what it must have been like for her stuck in this house with these people and they were driving her crazy.

"I decided to flip it so Elliot has this house that he loves and I thought about what it's like to have your space and house invaded by somebody else.

"It's playing with the 'an English man's home is his castle' cliché.

"I just tried to imagine all of the things that somebody could do if they moved into your home that, firstly, would irritate you and, secondly, would drive you crazy.

"It starts with them making a mess, not flushing the toilet, drinking all of his nice wine, locking his beloved cat out in the garden and it gets worse and worse and more sinister.

"They've also got Gemma's youngster sister Chloe there. When she first moves into the house, she never leaves her room. Elliot just sees her as a ghostly figure standing in the window," adds the best-selling author.

As part of his research for the book, he sought advice on the legal side of having unwelcome guests in your home and the lengthy process it could take to get them removed.

"If somebody comes to stay with you and refuses to leave it could take over a year to get rid of them. There is a section in the book when the solicitor explains to Elliot the whole process and he can't believe it and he realises he is stuck with these people for months," explains Mark, whose e-book Last of the Magpies won a Dead Good Read award at this year's Theakston Old Peculier Crime Writing Festival in Harrogate.

He says he hopes the book prompts strong reactions from readers. "I want them to love to hate the baddies. I want people to be shouting at the book with frustration at Elliot and the way he reacts to things and with anger and hatred at the in-laws.

"I really like to create these characters that people will remember and that fill them with so much rage and frustration.

"I also want people to think thoroughly about letting people come to stay with them. That's what a lot of early reviewers have said - they would be reluctant to let in-laws or anyone else come to stay," says Mark, who is inspired by writers such as Stephen King, Ira Levin, Ruth Rendell and Linwood Barclay.

Here To Stay was published in the UK by Amazon imprint Thomas & Mercer yesterday.

The storyline has already been well-received across the pond where it reached the number one spot in the Amazon US chart.

It will be followed by his next novel Far From Home - a story about a couple who are house-sitting in New York - in April.

And Mark has an extra reason to celebrate as sales of his books have past the three million mark.

"To be able to make a living from what I love doing is endlessly gratifying," says Mark.

The author will be appearing at Chase Book Fest at the Museum of Cannock Chase on September 21. For tickets call 01543 877666.