On Boxing Day, 1996, police received a strange call from a hysterical mother whose beauty queen daughter had disappeared, with a threatening ransom note left in her place.
It was the beginning of the grisly JonBenet Ramsey murder case, which has gripped the world for almost two decades, and remains unsolved as the 20th anniversary approaches.
But a true crime writing duo claim the crime was foreshadowed three days earlier, with another mysterious 911 call made from the luxurious Ramsey home.
Police in Boulder, Colorado, received a silent call on the evening of December 23, but when they rang back, no one picked up. An officer drove to the location from which the call had been made to check if anything was wrong.
A Christmas party was in full swing at the 15-room Tudor home, and the door was answered by a family friend of John and Patsy Ramsey, Susan Stine. She blamed the call on someone trying to order medicine for an ageing parent, who had not meant to use the emergency number. She would not let police in.
Lisa Wilson and Nick Van der Leek, authors of The Craven Silence trilogy, believe there was more to this call, and that those present may have become involuntarily complicit.
"We believe something happened at the party, something serious," they told news.com.au. "Secrets kept on December 23 were repeated under far more serious circumstances three days later. This time the Ramseys knew they could rely on their friends to keep their secrets.
"Their friends assumed the Ramseys were innocent, and if they felt otherwise later, they were ostracised, sued or accused."
Hours after Mrs Ramsey's Boxing Day call, police found 6-year-old JonBenet dead in the basement of the family home with a homemade garotte around her neck, a blow to her head and DNA in her underwear that still hasn't been identified. The family blamed an intruder who came through the open basement window.
"JonBenet had quite a lot of damage to her body," said Mr Van der Leek. "Her back showed scrape marks that suggest she was lying on her back, the garotting happening after she turned on to her stomach. I don't really see it was abuse or assault, it was something else - interference."
Ms Wilson and Mr Van der Leek have just released the third book in their series on JonBenet's death, coinciding with other recent shock revelations from television documentaries and media investigations into the murder.
A Colorado grand jury voted in 1999 to indict Mr and Mrs Ramsey, on charges that each "did unlawfully, knowingly, recklessly and feloniously permit a child to be unreasonably placed in a situation that posed a threat of injury to the child's life or health, which resulted in the death of JonBenet" and "did unlawfully, knowingly, recklessly and feloniously render assistance to a person [who had committed] murder in the first degree and child abuse resulting in death."
Then-District Attorney Alex Hunter's decision not to indict has long been controversial, and this weekend an explosive joint report by the Boulder Daily Camera and local news station 9NEWS found DNA evidence did not support the former prosecutor's decision to let the family off, since it indicated the samples came from at least two people.
In September's CBS docuseries The Case of JonBenet Ramsey, a panel of investigators alleged JonBenet's brother, 9-year-old Burke, was responsible for the murder, and the children's parents John and Patsy Ramsey covered up the crime.
The Craven Silence authors also believe the Ramseys covered up for their son, although they have a different theory about the murder weapon.
Burke, now 29, has strongly denied harming his sister, and said in a recent Dr Phil appearance that he suspected a paedophile who stalked child beauty pageants was the killer. He denounced the CBS documentary theorising he killed his sister as a "false and unprofessional television attack" that is riddled with "lies, misrepresentations, distortions and omissions" and has now filed a US$150 million defamation lawsuit against one of the panel members, forensic pathologist Dr Werner Spitz.
Ms Wilson and Mr Van der Leek allege Burke was jealous of his sister because she was beautiful, confident and shared her mother's passion for pageants. "She was like a little celebrity," says Mr Van der Leek, while her older brother was more awkward.
They believe he envied JonBenet receiving a generous bicycle for Christmas, when he did not. The Ramseys have changed their story over who did and did not get a bike.
"There was certainly an opportunity for kids to run wild a bit," said Mr Van der Leek. "It may have started in bedroom with a pillow-fight. JonBenet's room was a mess, there was pillow on the floor, one in the kitchen."
The authors allege she was killed after being struck over the head - only they believe he used a golf club or baseball bat rather than a torch left on the kitchen table as the CBS documentary claimed.
"There is very chilling evidence a child was involved in the crime," said Ms Wilson.
Unusually for the status-seeking family, there were no photos or phone records from that Christmas, with Mr Ramsey claiming he had lost his mobile. "If something is a first time or unusual event on the day someone is killed in their house, you have to ask why," Ms Wilson added. "The absence of evidence is often evidence."
Family friend Judith Phillips has told a story about Burke injuring JonBenet with a club a year earlier, while a housekeeper said he had smeared faeces in her bed and on one of her Christmas gifts.
They are two of the only Ramsey friends to have "broken ranks", according to the authors, along with the Whites. Both have faced lawsuits.
"Secrets were important to keep because of John Ramsey's massive affluence with [his firm] Access Graphics," they say.
After Mrs Ramsey's Boxing Day call, police found a strange, three-page ransom note apparently from a "small foreign faction" who demanded US$118,000 for JonBenet's return - the exact figure of her successful businessman father's bonus.
The note was written on Mrs Ramsey's pad (along with some practice drafts) and police repeatedly compared it to her writing, but could not draw a conclusive answer about whether they matched.
The Ramseys moved into the home of Glen and Susan Stine shortly after the murder and stayed for five or six months, even after Mr Ramsey returned to work. Mrs Stine, nicknamed "Patsy's pitbull", often drove the boys to school, and Mr Stine was even employed by Mr Ramsey.
"There was this incredible solidarity with them," said Ms Wilson.
"What's frightening about the case is the way a very wealthy family got everybody to dance," said Mr Van der Leek.
There are likely to be more revelations over the coming months as the anniversary approaches, and with Burke Ramsey taking Dr Spitz to court.
We can only hope it finally leads to justice for JonBenet.