Forget Grantchester and Midsomer, the new murder capital of England could very well end up being St Albans.

That is if up-and-coming author Rachael Blok has anything to say about it, after setting her fourth crime novel in the heart of the cathedral city.

She's bumped people off near Verulamium Lake and in the old Roman Theatre, and has now left a suspicious corpse at the base of the Abbey's 50ft tower. But did he jump or was he pushed?

Enter Dutch-born detective chief inspector Maarten Jansen, based out of the city centre's now-demolished police station, an outsider who cuts through the affluent veneer of St Albans during the course of her investigations.

"You know what St Albans is like, it's all super-polite and very, very lovely. I needed someone who cuts through all of that," she explained.

Apart from the Cathedral, The Fall also focuses on local mental health hospitals Cell Barnes and Hill End - combined in the novel as a solitary Hill Barnes - looking at how the treatment of women with psychiatric problems has changed over the last century.

Rachael said: "One of the most distressing aspects of researching the novel was reading many diary entries of patients of mental health hospitals over the last century. There are so many stories of feeling misunderstood, of manifestations of grief causing people to be admitted."

Although Stig Larsson and James Carroll have both mentioned St Albans, Rachael is unique in setting her novels in the city, although she is careful to avoid upsetting locals: "It's broader brush strokes because I don't want to be sued. I do know which café I'm referring to at times, but I never name them, although readers always ask!

"I did The Waffle House in the first one but called it something else, and put the old wheel outside. I was talking to them about it and they asked why I didn't call it the correct name! It's like my version of St Albans, it's been made to fit a commercial novel, it has to be tight and fit the plot."

So what next for Rachael? "There's so much here, there's so much history, so many possibilities."

And perhaps an appearance by the Herts Ad in a future novel? "I could easily put that in!" she promised.

Rachael will be attending an event at Books on the Hill with fellow novelist Harriet Tyce on May 10 at 7pm.