Zebo's flair can break the game open against Wales
The sub-plots are many and fascinating.
What about Jonathan Sexton versus Dan Biggar? What about Paul O'Connell versus Alun Wun Jones? What about Sean O'Brien versus Sam Warburton?
There is the Grand Slam at stake for Ireland; the Championship for Wales. Warrenball versus Joeball.
There is the almost irrelevant reward of a new winning record for the visitors and the knowledge for The Dragons that they have beaten these boys in green just twice in Cardiff over the last 34 years.
To even contemplate anything other than the supper-concentrated bubble of what will take place inside of 80 minutes would be rugby suicide for one and both.
Maybe, just maybe, the best indication of how far Ireland have travelled in the last 18 months comes from the once flamboyant figure of Simon Zebo.
He was nowhere to be seen when Andrew Trimble and Dave Kearney took the 2014 Six Nations by storm.
The misfortune of injury has gone his way this season in that he was given a glimpse and he took it with eyes wide open.
The one-game at a time focus that captain Paul O'Connell feels suits the Irish psyche has been adopted by what coach Joe Schmidt called a "free-spirited" Zebo.
He has taken to viewing the possibility of making history from an eleventh straight win as a secondary reward.
"I suppose it would be pretty special, but, at the end of the day, the focus is winning trophies, not setting these kinds of records," he said.
"You could have the best records in the world, but, if there is no silverware, it doesn't count for anything.
"We are fully focused on Wales and we know that if we put in a big performance that will contribute towards our own goal, that of doing well in the Six Nations."
The great entertainer has bought into the great adventure.
The details are on the money, the restarts, the ball placement and technique at ruck time, the work away from the ball.
Now, Schmidt is able to activate a wing wizard, astute to what his coach needs, with the knowledge that somewhere in there is that X-Factor which can turn a match with just a 'flick' of the ball.
It might have to take something special to break the game open.
Wales: L Halfpenny; G North, J Davies, J Roberts, L Williams; D Biggar, R Webb; G Jenkins, S Baldwin, S Lee, L Charteris, AW Jones, D Lydiate, S Warburton (capt), T Faletau.
Ireland: R Kearney; T Bowe, J Payne, R Henshaw, S Zebo; J Sexton, C Murray; J McGrath, R Best, M Ross, D Toner, P O'Connell (capt), P O'Mahony, S O'Brien, J Heaslip.
wales v ireland, tomorrow live rte2/bbc1, (ko 2.30)