Two men were driving along a remote mountain road in the middle of the night, searching for their brother after his car had crashed.
When they found the vehicle, lying on the ground nearby was the body of a young woman. Their brother was nowhere to be seen.
The woman - 21-year-old Jenna Watkins - had seemingly been thrown from the car and killed by the impact on the dark Bwlch mountain road in the south Wales valleys. It appeared to be a tragic, but not uncommon, accident.
But when Jenna's body was taken for examination, it told a very different story, detailed in a new documentary about the case.
Just a short time before the fatal scene unfolded on 21 April 2007, Jenna's mum Pauline had received a disturbing - and final - call from her daughter.
"About 10 to one, she rung me screaming and crying. I said 'are you strapped in?' She said no. I said 'strap yourself in', because I could hear the car going. And he's driving like a madman.
"I could hear him screaming at her. She was breaking her heart and I was screaming at her 'just strap in so you don't go through the windscreen'.
"Then the phone went dead."
"He" was Jason Shaddick, Jenna's partner, and the man being searched for by his brothers.
The couple had lived together in Neath.
Former Home Office forensic pathologist Dr Richard Shepherd told the BBC One Wales series: The Truth About My Murder that the evidence at the scene "pointed to a tragic road traffic accident".
Front seat passengers such as Jenna often have chest, rib and breastbone injuries if wearing a seat belt because of the massive pressure from the impact.
But Dr Shepherd said Jenna had none of these, "suggesting she'd been thrown from the car on impact".
Examinations showed severe bruising all over Jenna's body, especially her legs and head, but Dr Shepherd said there were no abrasions you would typically see from someone hitting the road.
"The initial theory of a car accident was just not adding up."
Daylight investigations at the scene were also raising questions - Jenna was found face down with jewellery and her possessions scattered around her.
Insp Emma White, the family liaison officer, said: "It didn't appear that she'd been thrown from the vehicle, just looking at the windows and things like that."
As the sun rose, Pauline received a visit from the police that devastated her life forever.
"I wouldn't let him tell me. I kept talking over him. He said, 'do sit down'. I said, 'no, I don't want to. I don't want to know.' Because I knew what he was going to say."
Shaddick was missing, but after an appeal he appeared at Neath police station where he refused to answer any questions.
With no other information to rely on, the work of the pathology team was to be crucial.
Fatal neck injuries are common in people flung from a moving vehicle. But examination of Jenna's neck revealed something different - her larynx had been crushed, suggesting extreme pressure had been applied.
Dr Shepherd said this, combined with the distribution of the bruising and no bone fractures meant "the appearances were starting to suggest strangulation".
When this was put to Shaddick, he responded in writing only.
White says: "He suggested he had crashed because he was being assaulted by Jenna and it was self-defence."
He claimed he put his arm around Jenna to calm her down and it was only when she went limp that he realised he had accidentally killed the woman he claimed to love.
With Shaddick refusing to answer questions, police turned to others to find out more about Jenna and the pair's relationship.
Pauline said Jenna almost died after contracting meningitis as a toddler and it made her determined to take extra special care of her youngest child.
Jenna frequently brought gifts and treats for her mum, wanting to "spoil" her.
Shaddick, 28, and Jenna were known in the area as a fun-loving couple who enjoyed socialising - he worked in a car parts factory while she worked in a call centre, both in Swansea.
Pauline said they were dubbed "the Hollywood couple" because they dressed so smartly.
But there was a darker side to their relationship.
White said: "They'd have riotous rows where they'd be screaming at each other. Jenna may have had to push him off on occasion."
Pauline had told White she previously found one of Jenna’s necklaces broken on the ground outside her house.
"Alarm bells were ringing particularly for me as a police officer because he'd previously ripped her jewellery off her body which is obviously very similar to this scene."
Jenna’s mother also described controlling behaviour by Shaddick, with Jenna changing clothes if he didn’t like them for fear of his reaction.
"He was horrible," said Pauline.
"Nasty. He was awful. Possessive."
Shaddick’s need for control had escalated into violence in the past. After speaking to previous girlfriends, White discovered Shaddick had two previous convictions for assaulting one of them.
Pauline once questioned Jenna about bruises on her body: “I said, ‘come home please. he’s going to really hurt you or he might kill you’.”
In the post-mortem examination, Dr Shepherd found old bruising across Jenna’s body, “most likely to have been caused by heavy blows from a clenched fist”.
Marks on Jenna’s cheeks and chin showed Shaddick was lying when he claimed he was the victim of her aggression.
"There seemed to be bite marks which looked as though they’d been made with some violence," Dr Shepherd said.
On the evening leading to her death, Jenna and Shaddick argued at a party in Port Talbot and Jenna left before he went after her in the car.
He claimed they continued arguing in the car because Jenna had taken cocaine and he disapproved. He said that he had only bitten her because she had hold of his testicles and it was the only way he could make her let go.
Toxicology tests on Jenna not only showed there was no cocaine in her body, but also that she had drunk very little alcohol.
In contrast, tests showed Shaddick had taken cocaine and had high levels of alcohol in his system.
Dr Shepherd said: "Her body shows how she desperately tried to defend herself. But she was beaten and bitten, and then strangled in a headlock which ended her life in seconds."
Shaddick was charged with murder and went on trial.
On 28 November 2007 he was convicted of Jenna’s murder and given a life sentence with a minimum term of 13 years. He was released in February 2021.
That sentence was not enough for Pauline.
"It's just not right. Thirteen years is nothing. The thought of him being out living his life... every time I go up the grave I get angry."
Pauline has kept Jenna's childhood bedroom exactly as it was when she died.
"I always feel close to her in this room. It's precious, this room is, to me. I like to have her photos everywhere I go so I can see her.
"Eighteen years is like nothing to me. Like all the other grieving mothers, you just don't move on."