The murder is one of the nation's most harrowing unsolved crimes, and now it's become the subject of a best-selling book
A PREGNANT woman's car breaks down on the side of a motorway. She leaves her children in the car while she walks down the hard shoulder to call for help - and her murdered body is found two days later.
The story sounds almost too creepy to be made up... and the chilling truth is that it wasn't.
The shocking death of Marie Wilks in 1988 is the inspiration for Belinda Bauer's new hit thriller, Snap, which is currently number three in the bestseller fiction lists.
Marie Wilks' murder shook the nation when the pregnant housewife was found with her throat cut on the side of the motorway, having left her broken-down car to call for help.
And as Marie's blood dripped from the dangling receiver of the emergency phone, her 11-year-old sister was walking down the hard shoulder looking for her, ignored by the hundreds of cars which roared past.
Thirty years on, it remains unsolved.
The heartbreaking story starts on the 18th June 1988, with 22-year-old Marie Wilks driving down the M50 in Herefordshire.
Marie, who was seven-months pregnant at the time, had been to visit her husband, Adrian - a soldier staying at a Territorial Army camp in the village of Symonds Yat.
It was her first big trip since passing her driving test, and on her way back home, to Wandon, she got lost.
Pregnant Marie had intended to avoid the motorway, but after becoming confused by a tangle of country roads, she had no choice but to put her anxiety to one side and take the only route she was certain would get her home - or so she'd hoped.
It was the early evening when Marie's car broke down - the worst possible thing to happen to an anxious driver in a time before mobile phones.
But Marie wasn't alone in the car. She was driving with her 11-year-old sister, Georgia, and her 13-month-old son, Mark.
With her car stuck in the hard shoulder, a nervous Marie was forced to leave the car and find an emergency telephone.
She told Georgia to stay put and look after Mark, and went to search for a phone. She never returned.
As the light started to drain out of the warm, summers' evening, Marie found a phone.
She called the police and explained that she was heavily pregnant, and had two young children with her.
The operator took her details and put her on hold as they tried to contact any family members who could pick Marie up. However, her dad was away on a fishing trip with the only other car the family had.
When the police operator returned to the line a few minutes later, the only sounds were those of cars speeding past.
"Mrs Wilks?" he asked. "Mrs Wilks?" Nothing. "Mrs Wilks?"
At around the same time, a patrolling police car saw an alarming sight: an 11-year-old girl walking along the hard shoulder, carrying a baby in her arms.
It didn't take long before police found an abandoned car, and then officers came across another chilling scene: an emergency phone receiver hanging by its cord - the caller nowhere in sight.
By the next morning, a nationwide search for Marie was underway.
Investigators noticed that there was blood splattered around the emergency call box Marie had used.
It wasn't for another 24 hours that they found Marie - lying on an embankment, three miles away from her broken-down car.
She'd been stabbed in the right side of the neck and her jaw had been broken.
Meanwhile, police raced to find the person responsible. A witness claimed to have seen a man walking down the hard shoulder near the scene of the crime, and police released an e-fit of the suspect.
A tip-off from a colleague then led to the arrest of 32-year-old ex-soldier Edward Browning, who worked at a nightclub in South Wales but was unknown to the victim.
Browning was travelling north to Scotland on the night of the crime, potentially placing him on the same stretch of the M50 as Marie.
In an eerie parallel, on the day of the killing, Browning had had a disagreement with his wife - who was pregnant herself.
The prosecution painted the picture of a violent man who took his rage out on a random, solitary woman when he had the chance.
It was enough for Browning to be found guilty in 1989, and he was sentenced to 25 years in prison. But incredibly, five years later, his conviction was overturned.
Judges found the conviction was unsafe because the police had kept back evidence from his trial.
An off-duty police officer had claimed to have seen a suspicious vehicle - the same make as Browning's - at the scene of the crime, but it was later revealed that the number plates didn't match Browning's.
As a result, the conviction was overturned.
Browning was awarded damages, reportedly in excess of £600,000. He died in May this year, aged 63.
The murder he was imprisoned for remains unsolved to this day, with Marie's family still no closer to finding out what really happened to her. Whether the flurry of publicity surrounding the new book will shed any new light on the case remains to be seen.
But one thing's for sure - readers of the book won't be able to shift the image of an 11-year-old girl carrying a baby down the hard shoulder, desperately looking for a big sister who would never come home.
