ONE of Nuala Ellwood's early memories is of traipsing around on her dad's heels after he'd returned from a difficult assignment overseas. Her father, Luke Casey, was a journalist who had been in Beirut covering the aftermath of the civil war. He returned home just a couple of weeks before the first hostages were taken.

Nuala was only about four or five years old. "And I remember following him around and thinking, the job that dad does is quite dangerous," she recalls.

It was clearly a powerful memory. Because when she came up with the idea for her first thriller, My Sister's Bones, she decided to make the protagonist a war reporter.

Not a man, though. The central character of Nuala's new novel, launched at Waterstones in York earlier this week, is a female war reporter.

They're a special breed says Nuala, who lives with her husband Nick and son Luke in York.

She once, as a young woman, went to a talk given by Marie Colvin, the veteran war reporter who was to be killed covering the Siege of Homs in Syria in 2012. "I remember her saying that bravery is not being afraid of being afraid," Nuala says. "I thought that was amazing."

She decided she wanted to capture that mix of strength and vulnerability in her own character, Kate Rafter. Kate is a war reporter who has been covering the siege of Aleppo in Syria. She has seen some awful things, and been powerless to do anything about them.

That's the thing about war reporters, says Nuala. Unlike the soldiers or medics they join on the front line, they're just observers - they're not doing anything obviously constructive. She has spoken to a couple of war reporters, who confirmed that that can lead to real feelings of guilt.

Despite her tough exterior, Kate's experience in Aleppo has left her emotionally shattered - subject to horrifying nightmares and hallucinations. A classic case of PTSD, in fact.

For Kate, the horrors are only just beginning, however. On learning that her mother has died, Kate returns to the old family home at Herne Bay, on the Kent coast. On her first night there, she is woken by a terrifying scream, which seems to come from next door.

The next night, she hears another scream. And she also sees a child flitting through the next-door garden - a child that nobody else has seen.

But are the screams and the child real? Or are they just in her mind, a manifestation of her PTSD? The reader doesn't know - and neither does Kate herself...

It is a novel that is filled with twists and turns. And Kate is very definitely an unreliable narrator, says Nuala. We really can't believe everything she says. But at the heart of the novel there genuinely is a very dark crime indeed. It may just not be the one you were expecting...

York Press:

Nuala hails from the North East - she grew up the youngest of five children on a smallholding near Darlington. For 15 years her dad commuted to work in London every week, always returning at weekends because he loved the family's country retreat so much.

But the family also took holidays on the Kent coast: they loved the light down there, and the way the sea meets the sky, she says, something which also inspired Turner and a host of other artists.

The plot of Nuala's novel was originally to have involved people trafficking. So setting it on the Kent coast somehwere near Dover seemed obvious.

Nuala spent a week in Herne Bay to soak up the atmosphere. And while ultimately the story didn't quite turn out as she'd envisaged, the Kentish seaside town was such a brilliant setting she kept it anyway.

It's a beautiful town, she says, with a long shingle beach on which Barnes Wallis tested his bouncing bomb. During the Napoleonic Wars it was a smuggling town - and many of the buildings have secret tunnels under them. There are also the remains of an old Roman fort near the town, with two towers known as The Two Sisters. "Local folklore says that the Romans made human sacrifices there," Nuala says.

All that makes Herne Bay a bit of a gift for a novelist, she admits.

She was there in February, out of season, when the town was oddly quiet. She went for a walk along the beach in thick fog. "It was mist so thick you weren't sure whether that was a person you were seeing or a shadow. It gave me some great images to work with..."

It has clearly worked. My Sister's Bones has arrived trailing ecstatic reviews and comparisons to Girl on a Train. It is "guaranteed to be this year's most twisty and twisted read," according to Ava March, the author of Untouchable. Amanda Jennings, who wrote In Her Wake, describes it as "a tense, atmospheric, deliciously dark story."

We'll leave you to judge for yourself...

BLOB My Sister's Bones by Nuala Ellwood is published as a hardback by Random House, priced £12.99.