There are storylines everywhere you look in Dublin this weekend.
Warren Gatland can expect an interesting reception from the crowd at the Aviva Stadium after his decision to drop Brian O’Driscoll from the last test of the Lions series, but that’s not the only Lions-related issue on the agenda.
There are players coming face to face all over the field, from whom the Lions coach had to choose between for various positions in his Test side. Many of them went Wales’ way, which could provide extra motivation for the men in green this Saturday.
Strip all those subplots away, though, and we are still left with the fixture that, perhaps more than any other in recent memory, has served up some real treats in the Six Nations.
Think back to the 2003 opener edged by Ireland in Cardiff, the 2005 fixture in which Gethin Jenkins galloped away to seal Grand Slam glory, or the 2009 thriller that saw Ireland claim a famous Grand Slam.
Take this to the bank and cash it: there will be tries, talking points and a clear pointer as to the destination of the title in Dublin on Saturday.
Here are five key matchups that will play a large part in who comes out on top.
Conor Murray and Mike Phillips share a number of traits as scrum-halves. Both are big No. 9s, happy to barge through a gap that smaller men wouldn’t back themselves into so successfully.
Their ability to operate as an extra back row forward at times often helps to keep their side rumbling forward. On Saturday, each man will need to be on his guard should the other opt to slip through gaps close to the breakdown.
In attack, their job is to feed their respective fly-halves, who like nothing more than a fast, flat pass to get their backs attacking the gain line.
Phillips seems a little slovenly at the moment and will need to regain that extra yard of urgency in Dublin, while Murray cannot expect the same armchair ride he got from his pack against Scotland. Each man, of course, may well be disrupted by the other side’s back row.
Sam Warburton will be doing his utmost to unsettle the Munster man, while Chris Henry and Peter O’Mahony will be hunting Phillips relentlessly.
The Lions captain has been reinstated to the starting line-up for Wales as a sign of the threat Warren Gatland recognises in the Irish loose forwards.
They had great success in isolating men and turning the ball over against Scotland, and the selection of Warburton is intended to try and fight fire with fire in the ground game stakes.
Henry was impressive as part of a pack very much in the driving seat against the Scots, but he has a bigger task on his hands to get the better of a rejuvenated Warburton. His work rate will need to be at its highest to clear the Welshman away from the tackle before he can clamp himself on to the ball.
Jamie Heaslip needed to step up to the plate in this championship.
Not only did he have to take on extra ball-carrying duties in the absence of Sean O’Brien, but it is time for him to come of age as Ireland’s captain.
He certainly filled both parts admirably against Scotland and will have to do so again this weekend.
He lost his Lions test place to Toby Faletau in the summer, as the Polynesian-born Welshman’s belligerence won the day. So, the Irishman might see this weekend as a chance to prove a point.
Ireland’s loose-head prop and Wales’ tight-head prop have both had to cope with the confiscation of their ability to win the "hit" at scrum time, thanks to the new laws.
It makes their head-to-head on Saturday an intriguing one. Jones’ strength at the initial engagement no longer gives him the upper hand, while Healy’s penchant for driving through his opponent has also been tempered.
Rather than winning the hit, their contest on Saturday now becomes a wrestle. Can Healy hold off the heavier man on his own put-in or will Jones get the shove on and disrupt Ireland’s scrum ball? It will be fascinating.
Everywhere you look, it seems there are battles between those chosen and those who lost out on Lions test caps last summer. The full-back position throws up another one.
Leigh Halfpenny had a curious afternoon against Italy, kicking his goals well but looking tentative in attack, which resulted in that uncharacteristic intercepted pass gobbled up by Michele Campagnaro. Kearney, on the other hand, looked like a man on a mission.
He kicked well, attacked with venom and scored a bullish try that capped Ireland’s win over Scotland. Space for both men on Saturday will be far less than they enjoyed against the tournament’s two worst teams, so their kicking game will be pivotal.
Whoever can pinpoint his touch-finders and up-and-unders to perfection will set his side up with threatening attacking positions.