WATCH: best-selling crime author Helen Fields talks to Phil Hewitt/SussexWorld

Drawing on her experiences as a high-flying barrister in London, Helen followed her dream of becoming an author around nine years ago, and after a spell in California, she moved to Sussex with her family two and a half years ago.

“I started writing in about 2014. I had left the bar and I was working with my husband and his media company. I left the bar after having my second child because I was just not seeing my children at all. The hours I was working were beyond reasonable. I was working all the time, evenings and weekends and if a nice family day came up, always I would miss out because always a case came up.”

It was time to move on – and writing re-entered Helen’s life: “From whenever I could write I was always writing stories and poems and songs and I continued until I was 18. I did drama and English for A Level and that was always my passion but I went off to study law and I just stopped. I didn't stop being a reader but I did stop writing. I went into the law and I absolutely loved it and absolutely don't regret it. It was challenging and fulfilling and it was an extraordinary life to have had for a while but really I had always been more interested in the arts and drama and the stories and it just felt natural to come back to it when I had the time and space to do so.”

By then, having been a barrister gave her the perfect background: “I was a criminal barrister and so I knew the process. I knew the personalities. I knew the police and had worked with victims and with experts and I had met murderers. I had all that in my arsenal and it was already there waiting. And when you're putting a case obviously you are in a way telling a story. A case comes across as a series of papers but what you are actually doing is building up the narrative. You're seeing it through the victim's eyes and the defence perspective and then from the perspective of the forensics. The story forms in front of you, and you realise that the story has to be layered and nuanced and that it has to be able to shift. If you're reading a book where that isn't the case, then it's just not going to be very interesting and that's what has filtered through into my writing.”

The latest chapter is The Institution, a claustrophobic, haunting crime thriller that will keep you up at night – perfect for those who couldn’t put down The Sanitorium and The Hunting Party, she suggests. In the book, they’re locked up for your safety. Now, you’re locked in with them. Dr Connie Woolwine has five days to catch a killer. On a locked ward in the world’s highest-security prison hospital, a scream shatters the night. The next morning, a nurse’s body is found and her daughter has been taken. A ransom must be paid, and the clock is ticking.