On the afternoon of 6 December 2006, two men in a blue Mazda pulled up outside a garage in Lambhill, in the north of Glasgow.
Raymond Anderson and James McDonald put on old man face masks before stepping out of the car.
What happened next was later likened by defence lawyer Donald Findlay KC to "a scene from The Godfather".
Dressed in trench coats, the pair walked into Applerow Motors, off the busy Balmore Road, and opened fire.
The owner, David Lyons, took cover but his 21-year-old nephew Michael was shot dead.
Steven Lyons, David's nephew, was injured along with his associate Robert Pickett, who lost a kidney.
The hitmen were enforcers for the Daniel crime clan, believed by police to be led by Jamie Daniel.
The Daniels were locked in a bitter battle with the Lyons family, who were based in Cumbernauld, North Lanarkshire.
A bloody gangland feud which had largely been conducted in the shadows was now headline news.
The deadly rivalry, which dates back more than 20 years, is now the focus of a new BBC Radio 5 Live true crime podcast.
Gangster: The Daniels and the Lyons chronicles the savage battle for control of Glasgow's drugs trade.
The six-part series also details the fall-out from multiple shootings and countless tit-for-tat attacks.
Ten days after the murder, David Lyons received a "ransom note" through the post.
It read: "The boys owe me £25,000 and I want what's owed to me. It's for drugs.
"They all know what it's about as they have got to pay the piper."
The High Court in Glasgow later heard that Mr Lyons did not pay the money and instead handed the letter to police.
Anderson and McDonald were placed under surveillance which eventually led officers to a house in the Garthamlock area where a machine gun, grenades and ammunition were discovered.
Both men were heard calling themselves "The Untouchables" and talking about the mysterious "piper", who was mentioned in the letter sent to Mr Lyons.
They were also linked to military weapons which had been stolen from army barracks.
In May 2008 Anderson, 49, and McDonald, 27, were convicted and each sentenced to 35 years in jail, which was later reduced on appeal.
The judge, Lord Hardie, described the killing as a "cold-blooded, premeditated assassination".
The murder was rooted in a feud said to date back to 2001 when a £20,000 stash of cocaine disappeared from a Daniel safe house in Milton, in the north of Glasgow, during a party.
Graeme Pearson, former director general of the Scottish Crime and Drug Enforcement Agency, told the podcast: "It was alleged that members of the Lyons family group stole a delivery of drugs that were due for the Daniel family and there had been a real upset about the theft of those drugs.
"Equally, it was alleged that the Lyons family had decided that they were also retailing in the north side [of Glasgow], where the Daniel family traditionally had the upper hand.
"This was their territory. This was where they made profit and they wouldn't stand for it. That couldn't go without some response."
The fall-out from the missing drugs rapidly progressed from car chases to shootings.
Among the early victims were Kevin "Gerbil" Carroll - a major figure in the Daniel clan - and Johnny Lyons, brother of David and Eddie Snr.
Both were shot and injured in separate attacks just 11 days apart in January 2003.
Then, in November 2006, Carroll allegedly used a 4x4 and a tow rope to topple the headstone of Eddie Snr's son Garry, who was only eight when he died of leukaemia in 1991.
The desecration of his grave marked a new low.
Days later Carroll ambushed and shot Eddie Lyons Jnr and a friend in Bellshill, Lanarkshire.
But a week later he was injured in a retaliatory shooting in Bishopbriggs, East Dunbartonshire.
Police were deploying significant resources in a bid to manage the dispute but the violence was escalating.
It was no secret that Carroll was the most unpredictable player in the whole feud.
His rivalry with the Lyons clan stretched back to his schooldays when he was reportedly bullied by members of the family.
Carroll, who earned his nickname from a character in the TV puppet series Roland Rat, later forged close friendships with the Daniel clan.
Aged 19 he was jailed for three months for car theft and by his mid-20s he was a major criminal player on the north side of Glasgow.
In 2004 he was charged with trying to kill a friend of Eddie Lyons Snr with an AK-47 but the trial later collapsed.
Carroll - who shared a £217,000 house with Jamie Daniel's daughter in Lennoxtown - could have been forgiven for thinking he was above the law.
By 2009 he was out of control and struck fear into rivals by masterminding a series of "alien abductions" across central Scotland.
The kidnappings were described in such a way as the victims, who were tortured and robbed, told police they couldn't remember anything about their ordeal.
Carroll's brutality and pattern of offending ensured he had many enemies and he went to great lengths to cover his tracks.
If his rivals wanted to target him then they would have to stage an audacious ambush unlike anything that had gone before.
On 13 January 2010 Carroll attended a lunchtime business meeting at Asda in Robroyston, Glasgow.
Days earlier he had shot and injured Eddie Lyons Jnr on the arm.
Now Carroll had arranged to poach drug pusher Stephen Glen, who was linked to the Lyons family.
A trial later heard Carroll, 29, told him: "You're working for me now. Anybody that doesn't fall into line is going to get banged."
But at 13:23, minutes after delivering the ultimatum, he was sitting in the back of a black Audi A3 when a speeding Volkswagen Golf screeched to a halt in front of the vehicle.
Carroll's two associates fled leaving him trapped in the back of the three-door car.
Two masked men emerged from the Golf and opened fire, shattering the rear passenger windows.
Carroll was shot in the head and chest - 13 times in total - in an attack that lasted 25 seconds.
William "Buff" Paterson, fled to Spain 10 days after the murder and later featured in a 10 most wanted appeal by the then UK Serious Organised Crime Agency.
But after more than four years on the run he eventually handed himself in at a police station in Madrid.
During his trial, at the High Court in Glasgow, Carroll's notoriety was highlighted when a list of 99 potential suspects was read out.
Paterson was later convicted and jailed for 22 years.
The judge, Lord Armstrong, told him: "It was not a spontaneous event which happened on the spur of the moment, it was in effect an execution."
The murder, which was committed in front of horrified lunchtime shoppers, was arguably the most public gangland hit ever carried out in Scotland.
It also paved the way for further brazen attacks.
In September 2015 Ross Sherlock was shot as he walked down a lane from St Helen's Primary School in Bishopbriggs.
At the time the kitchen fitter was chatting to another parent as their daughters walked hand-in-hand in front.
Two men were later cleared of the attempted murder.
And in January 2017, Ross Monaghan was shot outside St George's Primary School in Penilee, shortly after dropping his daughter off at school.
Five years earlier, he had been acquitted of murdering Carroll after a judge ruled there was insufficient evidence.
Two men later went on trial for the Monaghan murder bid but were cleared only to be later convicted of other organised crime offences.
In between the school shootings there was another major development.
Jamie Daniel, who became a millionaire after starting out as a scrap metal dealer in Possil, died of cancer in July 2016.
The convicted heroin smuggler made his fortune through drugs and, latterly, counterfeit cigarettes.
But his death, at the age of 58, left a power vacuum and the future of his crime group was cast into doubt.
There was no obvious successor, especially as his son Zander Sutherland was serving a 13-and-a-half-year jail term for heroin dealing.
Sutherland later fled the UK while on day release from prison and is now in Norway fighting extradition.
Meanwhile, the Lyons group responded to Daniel's death with a brutal campaign of intimidation against his associates, which included five attempted murders in five months.
Robert Daniel was the first target.
On 8 December 2016 his car was rammed by another vehicle before he was chased into a house in Robroyston.
Once inside he was struck twice on the back of the head with what he later told police was a hatchet or a machete.
Asked in court if he was aware of any ill-feeling between the Daniel and Lyons families, Robert, 29, replied: "Not that I know of."
A month later Thomas Bilsland, 31, suffered a fractured skull after he was set upon in Glasgow's Cranhill.
The next victim, Gary Petty, was targeted after he visited an Italian restaurant on 7 March 2017.
A court heard the 22-year-old was getting out his Volkswagen Golf when he was ambushed in Maryhill.
Ryan Fitzsimmons, 34, was attacked by a masked gang on 28 April 2017 outside his home in Clydebank, West Dunbartonshire.
The former soldier, who was left brain damaged, told the trial: "It felt like death was coming."
His mother Geraldine, 61, was so affected by what happened that she suffered a heart attack in the street.
Mr Fitzsimmons told jurors he had "no enemies" but jurors heard his older brother was once charged with shooting Ross Monaghan, the man cleared of murdering Carroll in 2010.
CCTV captures a car chase through Glasgow which culminated in an attack on Stephen "Bonzo" Daniel
The most savage crime on the 13-page indictment was the assault on Stephen "Bonzo" Daniel on 18 May 2017.
As he headed home after dropping off friends his Skoda Octavia was deliberately hit by a Volkswagen Golf in Milton.
An Audi S3 soon joined the chase through north Glasgow during which the vehicles involved reach speeds of up to 100mph.
Daniel's car eventually crashed on an off ramp of the M8 in the Port Dundas area.
The impact left him unconscious and the 39-year-old later told a court he had no memory of what happened next.
As he lay slumped at the wheel Daniel was subjected to a horrific attack with bladed weapons which left him with facial wounds so severe that first responders initially thought he had been shot.
The court also heard the ex-taxi firm director's car was found to have had a tracking device on it but he insisted he had no enemies before the incident.
Gangland investigations pose a massive challenge for law enforcement as detectives are typically met with a wall of silence.
But the sophisticated technology deployed by the Lyons group to plot the attacks also enabled officers to build a case against them.
And in May 2019 six associates of the family were jailed for a total of 104 years after being found guilty of five murder plots.
The judge, Lord Mulholland, told the gang: "You sought to turn Glasgow into a war zone for your feud.
"This is a civilised city, which is based on the rule of law.
"There is no place for this type of conduct, retribution or the law of the jungle."
Five years on, the feud - which has also been linked to a number of prison attacks - is back in the spotlight.
And presenter Livvy Haydock described the new podcast as the "most bloody and brutal" Gangster series to date.
She added: "This investigation has been eye-opening and uncovers the story of two of Glasgow's most notorious crime families.
"It's a vicious war which has raged on for 20 years and is still going on to this day."
Gangster: The Daniels and the Lyons is available as a boxset on BBC Sounds and on other platforms weekly.