The All Blacks and Ireland, two of the best teams in recent years, meeting in the Rugby World Cup quarter-final swiftly traverses the improbable to reality spectrum.
Either proud nation departing Japan this weekend was once unthinkable. This time last year, they were out on their own, seemingly on a collision course for the World Cup final.
How quickly that landscape altered.
At their first media call of this quarter-final week in Tokyo, the All Blacks stressed history is irrelevant. Who fronts now matters most.
While that's true, history does matter. It matters because it sets the scene for what has become a great rivalry, one from a New Zealand perspective that probably sits on par with the Springboks, which will sharpen minds and form a steely edge.
The All Blacks don't take kindly to defeat. After two in their past three tests against Ireland, there's no way complacency creeps in this week. Quite the opposite.
History also matters because it provides context to the trajectories of both sides, an element that builds or erodes the self-confidence of all individuals and teams.
On that theme the end of 2018 seems a lifetime ago for Ireland, not a mere 10 months.
Back then, Ireland were World Rugby team of the year, Joe Schmidt coach of the year, Johnny Sexton recognised as the best player on the planet.
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During that memorable run Ireland trumped all Six Nations rivals, all four Rugby Championship heavyweights. They were near unbeatable, losing one test in Australia.
Then, suddenly, the hunters became the hunted, the mantle possibly became too much to bear, and Schmidt's empire came crumbling down.
This year Ireland lost twice to England, once to Wales, when they were totally outplayed in the Cardiff rain after making a song and dance about leaving the roof open, and of course their shock defeat to Japan here which threw them into the All Blacks path earlier than anyone expected.
Ireland were first brought back to earth by England's brutal assault in the opening Six Nations game of the year. Schmidt confessed that defeat, not just the result but its nature, left Ireland broken.
Questions remain whether their belief and confidence has since recovered.
After the giddy heights Ireland reached last year, England were the first to expose that dominating collisions is enough to disrupt their prescriptive game, one based around retaining possession, Conor Murray's box kicks, carrying and defending strongly, and the odd trick play.
That South African-born Irish loose forward CJ Stander has no feeling in his face tells you plenty about their approach.
Getting the attitude and intent right in this area goes a long way to victory against Ireland.
Think back to 2016, and the response to their maiden defeat to Ireland in Chicago, and the All Blacks won the war in return test in Dublin that is remembered as one of the most physical occasions of the modern era.
There have been signs of recent life from Ireland. Their suffocating opening World Cup win over Scotland rejuvenated faith in Andy Farrell's defensive strengths. And they comfortably put Samoa away despite Bundee Aki's red card after 30 minutes.
In between times, though, they have been far from impressive.
In Tadhg Furlong and James Ryan, Ireland boast two of the world's best tight forwards. In addition to the air they will challenge the All Blacks set piece and target the breakdown.
But as rugby appears to swing from defence-dominated mantras to attacking-minded pace, skill and freedom of expression, Ireland have not adapted or adjusted. They appear the same team of 2018. Only now, opposition know the blueprint.
With ruck speed, offloads and width, Japan exposed Ireland in a performance that, no doubt, offered the All Blacks plenty of insight about where vulnerabilities lie.
The All Blacks' attacking pod structures, with Richie Mo'unga and Beauden Barrett pulling the strings from either side of the field, have advanced their game significantly since their loss in Dublin.
Ireland have, conversely, regressed in that time to land in a similar position to four years ago – carrying the burden of having never made it beyond this World Cup juncture.
For all the meticulous planning and preparation, for all the success of last year, Schmidt could not have asked for a tougher assignment.
Underdogs is where Ireland prefers to be. That such status is firmly entrenched this week signals just how far they have fallen. Last year a World Cup knockout match between these teams would be considered even odds.
To achieve history, and knock the All Blacks out, Ireland must again traverse the improbable to reality spectrum.