In the aftermath of the Euro 2016 draw in the French city of Nice, Martin O'Neill and Gordon Strachan exchanged pleasantries about the battles that lay ahead.
With a smile, Strachan later detailed the discussion with his Irish counterpart.
"He's started already with the first handshake, trying to tell me that the Irish are in trouble already," he quipped. "Do me a favour. He's a tricky geezer, him."
Sixteen months later, in a completely different atmosphere to the convivial mood in Mediterranean climes, the Scottish boss has arrived in Dublin with the opportunity to make life very difficult for O'Neill. Anything less than a win for the hosts tonight, and the Derryman will genuinely be in real trouble.
The vagaries of the computer-generated fixture list meant that this 'derby' was always going to be vital for Ireland. O'Neill spent his first year in charge contending that Aviva fortunes would determine his fate, and it was the back-to-back visits of Poland and the Scots that guided that theory.
September is usually a key juncture, but Ireland should have no problem taking six points from their double header with Gibraltar and Georgia. The result tonight will shape if it matters.
A win will suddenly make Shane Long's late leveller against the Poles in March look very significant, and keep the dream of automatic qualification alive.
A loss will render the rest of the campaign irrelevant. Another draw will effectively make third place and a play-off the best-case scenario, and that'd be dependent on favours.
This game is a border crossing, and it will either bring this Irish generation to the promised land or extremely uncomfortable territory. For the FAI, the stakes are high. For the dream team of O'Neill and Roy Keane, this match will represent the beginning of the end, or the end of the beginning.
"This is very, very important," said O'Neill. "Important for the nation, important for the players, for myself and the backroom staff."
During his pre-match press conference in Dublin Airport's Radisson Hotel, the recurring theme was the importance of a cool head under fire, an attribute that was absent from the frenetic loss to the Scots in Glasgow.
"I think it's a big occasion and you can't deny that," he stressed. "You have to play with the desire that the occasion demands but be composed as well. It's about being passionate and playing with a cool head."
The primary reason for Irish optimism is a reasonably smooth preparation in comparison to November, even in the backdrop of administrator-driven chaos.
It's taken a while for O'Neill to outline his idea of his strongest team, yet he is close to a full hand although a late hamstring injury suffered by Aiden McGeady has planted a seed of doubt.
After a rough experience in his hometown, the Everton trickster was desperate for revenge and a long-standing complaint may now scupper that goal.
He was below par against Poland when management gambled and it would be a surprise if they took another risk. "I will give him as much time as he needs," asserted O'Neill. "But he is feeling sore."
Robbie Keane was already a doubt because of an interrupted two months and the tragic death of his cousins has understandably hit the skipper hard. "If he feels he wants to participate in the game tomorrow, that will be entirely his decision," said O'Neill.
Everything we know about the Tallaght man would suggest he'll put his hand up for inclusion.
But, all things considered, Ireland's record goalscorer may have to settle for another cameo off the bench.
What should change from round one is the assurance of the Irish midfield with Glenn Whelan, James McCarthy and Wes Hoolahan all present.
Whelan's brief will be to restrict the movement of Steven Naismith and Shaun Maloney that hurt Ireland. The Stoke shield will need assistance from McCarthy, who has a dual purpose to drive on in the manner of the second half against Poles and help Hoolahan to pose issues higher up the park.
McCarthy will certainly have jeers from the substantial travelling support ringing in his ears and his boss expects him to be able to deal with that. This is a test of character for the 24-year-old, who has doubters to silence.
"His second-half performance against Poland was excellent and that will give him a lift," said O'Neill, "You have to be able to cope with these things (boos), that's what makes a player. And, besides, we'll have the bulk of the support."
If McGeady misses out, James McClean should come into the fray. A bold ploy would be to select both out and out wingers, but he chose Jeff Hendrick on the right against England with a brief to drop inside to bulk up the midfield and allow Seamus Coleman to bomb forward. Jon Walters is capable of assuming that responsibility.
When asked about replacing McGeady's spark and invention, O'Neill immediately referenced 'little Hoolahan', and while there's a tendency to presume that the Norwich schemer will slot in as a 'number 10', the alternative is that he functions as an unorthodox wide man.
He did so for periods of the Polish struggle.
"Here at home, when the onus is on us to find a piece of individualism, Wes has come to the fore," continued O'Neill. "He's an important player."
Should Walters be required elsewhere, then Shane Long and outsider Daryl Murphy would compete for the central striking role.
There is room for Long, Walters and Hoolahan in the same side and it's a scenario that would present the scope for flexibility within the game if Plan A falters.
What is essential is building the platform that allows Robbie Brady and Coleman to affect proceedings in the opposition half. "We will be positive," promised O'Neill. The full-backs have to influence that.
Scotland know that stopping their raids will starve the hosts of attacking diversity; Ikechi Anya kept Coleman busy last time out and Ireland looked one dimensional.
Under Strachan, the Scots have a unity of purpose, a sum that is better than the parts. Their personnel is far from intimidating.
Steven Fletcher, a scorer of one league goal in 2015, leads the line. Charlie Mulgrew, outstanding in midfield in November, may be required in a makeshift central defence next to Norwich's Russell Martin. They can be ruffled.
Alas, O'Neill has articulated his fears about Ireland's troubles in the final third.
Raw desire has carved out the late goals that have kept French ambitions intact; the public is waiting for a stand-out performance to inspire real belief.
Still, the 63-year-old didn't take kindly to a question which inferred that progress has stagnated since John O'Shea's German equaliser.
"I don't actually see it that way," he countered. "We got beaten by Scotland with a goal in the 75th minute. We drew with Poland. We've a campaign of 10 games and have to get x number of points to qualify. We landed a pretty tough group here and everyone accepts that."
Will spirit be enough?
"It's a start and a help and it can carry you a distance," replied O'Neill. "You need other things of course to win big games."
The fear is that this Irish group will be unable to avoid the draw that's one too many.
Verdict: Ireland 1, Scotland 1
Some disgruntled Irish football fans have paid for a banner protesting against FAI chief executive John Delaney to be flown over the Aviva Stadium ahead of Ireland's crucial Euro 2016 qualifier with Scotland.
This is the time for leadership and good management. Anything less than a win against Scotland will place Ireland in a very difficult position and it is in these circumstances that the best managers do their best work.