An emerging force against a wounded champion. High-octane flair versus ruthless structure. A maverick fly-half opposite a colossus of the sport.
Scotland, a growing power under Gregor Townsend, eased past Italy in the opening round of the Six Nations despite a late defensive lapse.
Defending champions Ireland arrive at Murrayfield on Saturday having been thumped by England in Dublin.
How will Joe Schmidt's men respond to the chastening loss? Can Scotland continue their rise and claim another scalp? Here are four key questions for the round-two tussle.
Scotland have won their past seven Six Nations matches at Murrayfield, including an impressive victory over Ireland two years ago.
They ran a monstrous South Africa close in Edinburgh last November and the world-leading All Blacks even closer a year before.
Townsend's men brushed Italy aside with little bother. Beating this Ireland team, the second-best in the world, even after their England humiliation, will be significantly harder.
This game will tell us a lot about where Scotland are and whether they have the skill and the mettle to mount a credible title bid.
Can you recall Schmit's Ireland taking such a monumental physical pounding as they did against England - let alone on their own patch?
Eddie Jones' side had the beating of them in the collisions, making 49 dominant tackles to Ireland's six, at the breakdown and in the air.
It was just the second Ireland defeat in 20 matches. Andrew Porter had never lost in his 11-cap career, while Jacob Stockdale, James Ryan, Jordan Larmour and Bundee Aki tasted defeat for only the second time.
Scotland may not have the beef in their ranks to bully Ireland as England did, but does an Ireland backlash beckon, or can the hosts find a different path to victory?
Finn Russell excelled in Scotland's opening-round victory over Italy
The swashbuckling Finn Russell versus ultra-intense world player of the year Johnny Sexton.
Russell plays with flamboyance and is flourishing at Racing 92 after joining the Parisian club from Glasgow Warriors in the summer. He seems to have rid the inconsistencies from his game in France.
The fly-half shone against Italy with two delightful kick assists and some excellent decision-making under pressure. You can bet the Ireland defence will try to disrupt his play-making flow.
Sexton is ruthless and orchestrates a more structured - and effective - Ireland game plan. A two-time British and Irish Lion, he has won three Pro14s, four European Champions Cups and three Six Nations titles.
England prevented the Leinster man exerting his usual imperious influence last week. Getting Russell front-foot ball and stifling Sexton will be key to Scotland's chances of success.
Much was made of Scotland's pre-tournament injury list, a group that swelled to 20 when Hamish Watson damaged a hand in Edinburgh's win over Montpellier.
Sam Skinner, the in-form Exeter Chiefs lock/flanker, and Edinburgh tight-head WP Nel joined them after being forced off against Italy.
But, while other frontline operators such as John Barclay, Zander Fagerson, Blade Thomson, David Denton and Duncan Taylor remain sidelined, some of the walking wounded are available again.
This week Townsend welcomes back wing Sean Maitland and lock Jonny Gray to his starting side, and hooker Fraser Brown and centre Pete Horne on the bench.
While Scotland are closer to their strongest 23 than last week, this will still be a giant test of their resources.