Chilling eight-word plea mum made in 911 call after finding out 6-year-old daughter was missing on Boxing Day

A brand-new documentary about one of America's most puzzling cold cases has just dropped on Netflix.

The three-part series looks into the seriously unsettling case behind six-year-old JonBenét Ramsey's murder which took place on Christmas Day back in 1996.

Scrutinising the missteps of law enforcement and the media, the doc puts forward new routes authorities could take to finally bring the killer to justice nearly three decades on from the heinous crime that shocked the world.

Check out the official Netflix trailer here:

On 26 December 1996, JonBenét's parents, John and Patsy, awoke to a nightmare which would go on to haunt their family for years to come.

Patsy had gone downstairs to make coffee on Boxing Day morning while John was shaving when she found a piece of paper left at the bottom of her stairs.

In an interview from 1998, Patsy explained: "I got up and got dressed, you know, it was very early, not daylight yet.

"I just started downstairs to get coffee on or whatever, as I moved toward the end of the stair, there were these pieces of paper lying on one of the runs of the stair."

After reading the 'first couple lines' Patsy soon realised what the piece of paper was - a ransom note.

After it 'clicked' what the note was, a 'panic-stricken' Patsy 'bounded back up the steps' to JonBenét's daughter and found she wasn't in her bed.

The ransom note Patsy found that morning was addressed to her husband, John, and instructed him to 'listen carefully'.

"We are a group of individuals that represent a small foreign faction," the note began. "We respect your bussiness [sic] but not the country that it serves.

"At this time we have your daughter in our posession [sic]. She is safe and unharmed and if you want her to see 1997, you must follow our instructions to the letter."

The demands involved John withdrawing $118,000 from his account, which later called a 'bizarre' sum, instructing: "$100,000 will be in $100 bills and the remaining $18,000 in $20 bills."

John was told to put the money in a 'brown paper bag' and wait for the 'kidnapper' to call him 'between 8 and 10 am tomorrow to instruct you on delivery'.

"The delivery will be exhausting so I advise you to be rested," the note continued. "If we monitor you getting the money early, we might call you early to arrange an earlier delivery of the money and hence a [sic] earlier delivery pickup of your daughter."

Taking a more sinister turn, the ransom note then threatened: "Any deviation of my instructions will result in the immediate execution of your daughter. You will also be denied her remains for proper burial.

"The two gentlemen watching over your daughter do not particularly like you so I advise you not to provoke them. Speaking to anyone about your situation, such as Police, F.B.I., etc., will result in your daughter being beheaded.

"If we catch you talking to a stray dog, she dies. If you alert bank authorities, she dies. If the money is in any way marked or tampered with, she dies."

The 'kidnappers' declared John stood a '99% chance' of killing his daughter if he tried to 'out smart' them, adding: "Follow our instructions and you stand a 100% chance of getting her back.

"You and your family are under constant scrutiny as well as the authorities. Don't try to grow a brain John. You are not the only fat cat around so don't think that killing will be difficult."

The note concluded: "Don't underestimate us John. Use that good southern common sense of yours. It is up to you now John! Victory!"

It was signed off 'S.B.T.C'.

John explained that he instructed Patsy to 'call the police' immediately after reading the note - a call which Netflix included snippets of in the documentary.

The exact call made at 5.52am the day after Christmas heard Patsy screaming: "We've had a kidnapping! Hurry, please!"

"Explain to me what's going on, OK?" the operator responded, prompting Patsy to reply with an extremely harrowing eight-word response that no doubt will leave chills in any parent watching.

"There's a note left and our daughter’s gone," she pleaded before begging: "Please!"

John described finding the ransom note as a 'punch to the stomach that's just severe'.

Later in the documentary, we find out that the day took a devastating turn as John eventually discovered JonBenét’s lifeless body in the basement - despite the fact police had already searched the property when she was first reported missing, which was later branded a 'major mistake' on their behalf.

"Her body was right there in front of me," John recalled.

Following an autopsy, it was revealed that JonBenét had been sexually assaulted and brutally murdered in her own home.

Boulder police, who were admittedly inexperienced in handling homicide investigations, quickly turned their suspicions toward the Ramsey family which went on to ignite a decade-spanning media frenzy that painted them as the prime suspects.

This was despite the fact there was no DNA evidence from John, Patsy or their other child, Burke, found on JonBenét that would point to them as the potential murderers.

Such reporting sparked a nation-wide obsession with the case, leading to a number of extremely conflicting theories described as a 'poisoned well' of false information. The case remains unsolved 28 years later.

Cold Case: Who Killed JonBenét Ramsey is currently available to stream on Netflix.