Seven teenagers walked past a Ford Fusion car parked outside a court in Bishop Street, Londonderry, Northern Ireland, at 7.39pm on January 19.
CCTV footage captured the group laughing and joking as they walked down the street and out of vision.
Thirty minutes later, the same CCTV camera showed the car exploding in a ball of flames, the sound wave ricocheting throughout the small city nestled in the valley of the River Foyle, causing the windows and doors in houses two miles away to tremble.
Rewind the CCTV footage 46 minutes, and the car can be seen being driven into the street and parked before a young man wearing a hooded sweatshirt gets out and runs away.
Police efforts to investigate the attack in the following days were hindered by continued security alerts and hoax bomb threats. Nonetheless, the city’s chief police officer was sure who was responsible – the “New Irish Republican Army”.
International journalists were already scrambling to the city to report and analyse the significance of the car bombing.
The level of interest almost indicated that the attack was something new, but it wasn’t.
Since 2009, organisations that want to continue the Irish republican tradition of “armed struggle” against British rule have claimed responsibility for a string of killings of British soldiers, policemen and prison officers.
What journalists wanted to know was to what extent their activity now relates to the political drama of Brexit unfolding in London.
Northern Ireland, like Scotland, voted against Brexit in the June 2016 referendum, while Wales and England wanted to leave the bloc.
Since the vote, people in Northern Ireland have found themselves in front of TV cameras more than any time since a peace agreement ended 30 years of sectarian violence in 1998.
Like the rest of the community, we're absolutely disgusted by what has happened here. I would love to hear someone try to explain why they did what they did in our busy city centre with lots of people about. They have heard the outrage of the community.
That conflict pitted pro-British, mostly Protestant unionists, dedicated to retaining Northern Ireland’s place in the United Kingdom against Irish nationalists, mainly Catholic, who wanted to unite with the Republic of Ireland.
Peace was reached when the two blocs agreed to share power, and allow the constitutional future of the province to be decided by popular vote when the right time came.
It was facilitated by the UK and Republic of Ireland, both European Union member states, allowing their governments to remove trade and security barriers along the controversial border that reminds nationalists that the island of Ireland is still divided into two separate countries.
Britain’s withdrawal from the EU threatens to make that border more significant and more visible.
Justifiably, the media has been quick to point out the combustibility of the situation, and hawkish in spotting any signs that stability in the province might be deteriorating.
But suggestions that hardline Irish republicans intent on using force to achieve their goals are in some way motivated by Brexit is perceived almost as an insult by those paramilitaries who pride themselves on their ideological purity.
Infrastructure or none, the border that divides Ireland exists, and for them, it is a symbol of occupation.
The New IRA said as much when it eventually took responsibility for the Derry car bomb.
“All this talk of Brexit, hard borders, soft borders, has no bearing on our actions and the IRA won’t be going anywhere,” its statement read.
Republican hardliners who believe Sinn Fein has sold out to the British government have peeled away from mainstream republicanism at various stages of the peace process.
In 2012, a collection of these dissident groups joined forces and rebranded themselves simply, “the IRA”.
For everyone else, they became known as “the New IRA”.
Quite systematically, British intelligence has set about dismantling this group with surveillance and informers.
In the last seven years, they have identified a number of arms dumps and made arrests that have crippled the New IRA, everywhere but Derry.
According to Allison Morris, security correspondent for the Irish News, Derry became a blackspot in the security services’ efforts to thwart dissident republican violence.
As such, the threat there has not just grown, but evolved.
“Elsewhere it’s just disenfranchised former members of the Provisional IRA, but that’s not the case in Derry. These are new recruits, people who were too young to be involved in the conflict,” she said.
That growth has seen Derry become something of an ideological battleground between the dissidents and Sinn Fein to win the hearts and minds of young working-class people in nationalist housing estates.
Where the dissidents have prevailed, violence has often followed.
Last summer, the New IRA was widely blamed for orchestrating sectarian rioting during the annual Protestant marching season.
For six nights in a row, the city’s only Protestant housing estate to the west of the River Foyle was pelted with petrol bombs.
Some of the most trenchant condemnation of last month’s car bomb came from the local Sinn Fein Member of Parliament, Elisha McCallion.
Speaking to Al Jazeera, she said: “Like the rest of the community, we’re absolutely disgusted by what has happened here … I would love to hear someone try to explain why they did what they did on Saturday night in our busy city centre with lots of people about… they have heard the outrage of the community.”
But for dissidents, this just reinforces their view that Sinn Fein has betrayed republicanism.
If it hadn't been for armed struggle, Martin McGuinness would have been a butcher and Gerry Adams would have been pulling pints in a bar on the Falls Road. For them to condemn young republicans now is the height of hypocrisy.
Packy Carty is a senior member of the dissident republican party Saoradh.
The group is accused of having formal links to the New IRA, and five of its members were arrested after last month’s bombing – all have been released.
It denies those associations, and saves its most stinging criticism for Sinn Fein, who Carty doesn’t regard as legitimate republicans.
“If it hadn’t been for armed struggle, Martin McGuinness would have been a butcher and Gerry Adams would have been pulling pints in a bar on the Falls Road,” he said. “For them to condemn young republicans now is the height of hypocrisy.”
Not all of those who disagree with Sinn Fein’s politics would go as far as excusing or condoning continued violence.
In a lengthy blog post, former Provisional IRA member and Sinn Fein critic Anthony McIntyre wrote: “It seems unfathomable that there remain republicans so divorced from the concept of rights other than their own, that they would still consider detonating a car bomb in a population centre.
“If the Provisional IRA couldn’t succeed, and their campaign was an unmitigated failure, then what chance have these make-believe IRAs got?”
Ultimately this is the point, and it strikes at the heart of the differences between Sinn Fein’s pursuit of a united Ireland and the tactics of dissident republicans.
Brexit might not matter to the hardliners, but it has given Sinn Fein the political momentum to push for a public vote on Northern Ireland’s future.