The Kinahan-Hutch feud violence has been characterised by a period of rapid bloodletting in the early part of last year.
That was followed by relative calm as the Garda redoubled their efforts and the criminals hid from each other.
To date 12 people have been shot dead; two in Spain, one in Meath and nine in Dublin.
It has been a feud of two halves; nine murders between February and August last year and just two killings in the 9½ months since.
A four-month break in the murders at the end of last year was shattered just before Christmas when Noel Kirwan was shot dead outside his partner's house in Clondalkin.
Wednesday's gunning down of father-of-two Michael Keogh (37) in Dublin's north inner city brought to an end a five-month murder-free period since Kirwan's killing.
There are now real fears that the killing by the Hutch faction of Keogh, who was aligned to the Kinahan gang, will now see the gun violence ramp up.
How it began
The killings began when Gary Hutch (34) was shot dead on September 24th, 2015, at an apartment block near Marbella in southern Spain.
He was murdered by the Kinahan drugs gang, of which he was once a member, after it accused him of supplying information to the police.
He had also tried to shoot a senior gang member.
Back in Dublin, his family had negotiated with gang leader Christy Kinahan for months in an effort to spare his life.
Some €200,000 was paid and Gary Hutch was told he could return to Spain. However, the deal was reneged on and Hutch was murdered.
Three months later Dubliner Darren Kearns (34) was shot dead in a pub car park on Blackhorse Avenue, Dublin.
His murder on December 30th, 2015, has now been linked to the Kinahan gang. It is believed Kearns and another criminal were behind a botched gun attack against its members in west Dublin weeks earlier.
It was not until February 2016, when a killing team stormed a boxing match weigh-in at the Regency Hotel, north Dublin, that the Kinahan-Hutch feud was firmly planted into the public consciousness.
David Byrne (35) was shot dead in the attack but other gang members escaped on foot.
Footage from the weigh-in as the armed men stormed the room was captured on the mobile phones of those present and published online almost immediately.
When the Irish public saw the newspapers the following day, the shock was complete.
The front pages were filled with images of armed gangsters dressed as a Garda SWAT team running to and from the Regency.
The unprecedented pictures brought home the horror and brazenness of the attack, thrusting it into the middle of the general election campaign.
Photographers were observing the weigh-in on the day, from outside the hotel, hoping to get shots of known gangland figures expected to be there.
When the extraordinary scenes unfolded the cameras were at the ready.
Much of the public debate centred on why crime journalists and photographers thought to be present but nobody in the Garda was carrying out surveillance despite Irish drugs wholesalers based in Spain expected to be there.
Burst of extreme violence
Just three days later Gary Hutch's uncle, Eddie Hutch (59), was shot dead at his north inner city home.
All of the 12 killings to date bar two – including Michael Keogh’s – have been one-way traffic; Kinahan on Hutch.
A close associate of the Hutch family, Noel Duggan (55) was shot dead outside his home in Ratoath, Co Meath, on March 23rd, 2016.
Duggan, nicknamed "Kingsize", was heavily involved in cigarette smuggling and was very close to the Hutch family patriarch Gerry Hutch, the veteran criminal known as "The Monk".
Martin O’Rourke (24) was shot dead on Sheriff Street, Dublin 1, on April 14th after being mistaken for a Hutch family associate.
Michael Barr (35), a Hutch associate and dissident republican, was shot dead in a pub in Summerhill, Dublin 1, on April 25th.
Gareth Hutch was shot dead on May 24th on North Cumberland Street, Dublin 1.
A close associate of Wednesday’s murder victim Michael Keogh is a suspect for the murder of Gareth Hutch and gardaí suspect he was shot dead to avenge Hutch’s murder.
David Douglas (55), Killala Road, Cabra, was shot in the doorway of a shop he ran with his wife on Bridgefoot Street, Dublin, on July 1st, 2016.
He was a friend of Darren Kearns, murdered by the Kinahans on December 30th, 2015.
The Kinahan gang believed Douglas and Kearns acted together on a botched gun attack in November 2015, against its members.
Dublin City Council worker Trevor O'Neill was shot dead in Majorca on a family holiday with his wife and young children on August 17th last year after he was mistaken for a member of the Hutch family.
Between March and August the feud claimed one life per month.
There was then a lull, broken by the Christmas week killing of Noel Kirwan, as huge Garda resources have been applied, especially on the streets of Dublin’s north inner city.
Kirwan was gunned down because he was close to the Hutch family, rather than a gang member.
And with the first feud killing of this year having unfolded on Wednesday, the Garda focus is now two-fold; to catch Keogh’s killers and also manage the tensions his murder has created.
To date they have been hugely successful in bringing criminal charges, up to and including murder charges, against suspects and in seizing cash and firearms.
However, while the Garda’s resolve is resolute and resources are being poured into policing the feud, the rival gangs are similarly well resourced.
They are clearly willing to be patient and can still find willing gunmen to kill for payment.