A haunting mix of whodunit and history made Elly Griffiths' Dr Ruth Galloway series a million-selling bestseller. This Halloween she was in Norwich to launch her latest novel

East Anglia has haunted her novels from the beginning.

Ghost stories on the Broads and a walk on coastal marshes first inspired Elly Griffiths to conjure her best-selling Dr Ruth Galloway series from the Norfolk landscape.

So a Halloween launch in Norwich was perfect for her new thriller, The Stranger Diaries.

This latest book mixes contemporary crime with a creepy Victorian atmosphere.

The haunting read stars creative writing teacher Claire, who specialises in fictional gothic writer RM Holland (partly based on MR James who had his own East Anglian links.) When a colleague is killed and a quote from an RM Holland is story found by the body, it becomes clear the writer's work holds the key to the case.

Afraid the murderer might be someone she knows, Claire confides her suspicions to her diary. Then she sees someone else's writing in her journal...

A Q&A and some spooky places:

Where have been some of your favourite Norfolk and Suffolk places to set your stories?

Norfolk and Suffolk are so beautiful and so rich in history, it would be hard to pick a favourite place but I have a soft spot for Holme, Holt, Beccles and Blakeney. Norwich is one of my favourite cities and I haven't got close to discovering all its secrets.

Do you teach creative writing, like the heroine of The Stranger Diaries? Do you have a top tip?

Yes I teach on a creative writing MA course. My top tip would be: start writing today, don't wait for inspiration to strike. As Picasso said 'the muse catches you working'.

Do you keep a diary yourself?

I've kept a diary since I was 11. I used to write every day but now it's probably more like once a week. I find it very therapeutic although, in retrospect, my teenage journals are extremely embarrassing.

Is RM Holland based on a real writer

He's fictional but I did draw on people like MR James and WW Jacobs (author of The Monkey's Paw)

Are there places still waiting for a starring role in new Dr Galloway books?

She needs to explore the Neolithic flint mines at Grimes Graves.

What are the spookiest places you know in Norfolk?

Titchwell Marsh is pretty spooky at times as are parts of the Norfolk Broads. My aunt used to tell a very scary story about Acle Bridge.

What scares you?

I love ghost stories and I'm not easily scared. My only real fear is a universal one - something bad happening to someone I love.

Elly, whose real name is Domenica De Rosa, has been visiting family in Norfolk since childhood. Her million-selling Dr Ruth Galloway series is set in the county – with locations including the maze of ancient chalk pits, tunnels and crypts beneath Norwich; the pilgrim village of Little Walsingham and a Second World War airfield on the coast. Modern landscapes and real history are interwoven with the ancient past and fictional plots. One of the series, A Room Full Of Bones, begins on Halloween night in King's Lynn. This Halloween night Elly was planning to uncover some more terrifying tales of Norfolk by joining the Norwich Ghost Walk.

The plot of her first Ruth Galloway novel, The Crossing Places, came to her as she was walking with her archaeologist husband on the marshes near Titchwell on the north Norfolk coast . As he told her how prehistoric people believed marshland was a sacred place, neither land nor sea, neither living nor dead, but a bridge to the afterlife, she saw a story of a missing child and an ancient henge, of modern policing and distant history.

Her next Ruth Galloway book, to be published in February, comes full circle back to the marshes between Titchwell and Holme – and summons an unsettling version of Norfolk's Jack Valentine legend.

It is one of the folk stories she first heard aboard her auntie Marjorie's boat on the Broads. 'My aunt used to know lots of really good ghost stories. We would be gliding along the Broads and she would be telling these stories,' said Elly.

Now she tells her own haunting stories.

The Stranger Diaries, by Elly Griffiths, published by Quercus is a Radio 2 Book Club pick. It was launched in front of more than 100 fans at a special afternoon tea at Jarrold.

Elly Griffiths has been shortlisted for Crime Novel of the Year three times and won the CWA Dagger in the Library Award.