Leinster, near imperious on the way to three Investec Champions Cup finals and a semi-final in the last four years, have arrived back into the last four in a different fashion this time around.
If Leo Cullen and Jacques Nienaber have been hatching a cunning plan to lull Toulon into a false sense of security by stumbling and stuttering and handing out intercept tries like sweets, then they may have succeeded.
We'll know more at 5pm this evening when Leinster will either be looking forward to a Bilbao blockbuster against Bordeaux-Begles or Bath, or wondering, once again, where it all went wrong.
Defeat today at Aviva Stadium, in a game they start as 11-point favourites, would lead to some serious questions about the coaching ticket and whether or not, after eight seasons of chasing a fifth star, something needs to change.
"It's a game they have to win because I just think they can't afford to lose it," was how former Ireland captain Donal Lenihan summed up their predicament.
Last season's Northampton Saints semi-final shocker appears to have haunted the team this year and the only way to exorcise the ghosts is a return to a Champions Cup final in a venue that is filled with happy memories.
Sam Mames was the scene of their last triumph in 2018 and although the game itself against Racing 92 was forgettable fare, the return to the summit was special.
But the scar tissue from the last seven renewals of the competition and the scarcely believable dramatic nature of the defeats is this current team's legacy.
Desperation to recarve that inscription will be a driving force today in Dublin 4 where over 35,000 are expected to attend.
Leinster's six defeats in the URC - including last weekend's reverse at Benetton, where they had sent a very strong team - is a huge cause for concern.
While they sailed past Sale in the quarter-final, they diced with death against Edinburgh in the previous knock-out round, giving up three first-half interceptions and trailing with 25 minutes to go.
Prior to that, the pool victory over nemesis La Rochelle was thanks to a minute of madness when three errors allowed Leinster to go from their own goalline to kick the winning penalty with the clock in the red, while the success over Bayonne came down to the bounce of a ball.
It would be impossible for Toulon to see all that and not arrive at the conclusion that this team, who also accounted for Harlequins and Leicester in the pool, is far from unbeatable. Too many times this season they have looked vulnerable.
The French side, who have had a mixed Top 14 campaign and sit eighth, have lost just once in Europe this season, a group-stage loss at Edinburgh.
They finished second in Pool 2 after home wins over Bath and Munster and away to Gloucester. After that they dug out a one-point win over Stormers and a three-point win at Glasgow.
The threats in the backs come from joint top try-scorer Gael Drean (7), Ben White and Nacho Brex (below) but they are benefitting from the heavy lifting done by their forward pack.
Back-five forward Charles Ollivon leads the way in a unit that leads the competition with 44 scrums won.
The France international racked up 21 tackles against the Warriors, while back row Esteban Abadie, who only makes the bench, is getting an average of 2.7 lineout steals per 80 minutes.
Loosehead Jean-Baptiste Gros was outstanding in France's Six Nations win, starting all five games.
As for Leinster, they've changed seven from the side that lost last weekend to Benetton with Rieko Ioane switching to the wing.
Andrew Porter (below) is back for his first action since the start of April but it's more about who is missing for Leinster that causes more concern for the teams' fifth meeting and first since 2015.
Tadhg Furlong, RG Snyman and Ryan Baird would likely have all started, while James Lowe misses out after just returning to training following a groin injury; Max Deegan is suspended.
The impact of those absences filters down to the bench where Scott Penny (five European appearances off the bench), Jerry Cahir (three as a replacement) and Alex Soroka (European debut) take their places.
Hooker Dan Sheehan has been Leinster's best player this season and it would not be a surprise to see him do the full 80 if needed, redeploying to the back row - as he did against Sale - in the latter stages.
This is where the pressure ramps up. Not even last year's URC decider carried the weight that this one does as Leinster go looking for a first-ever victory over the three-time winners.
"We're all trying to climb the mountain, aren’t we?" said Cullen, a three-time winner as a player and once as a coach. "And we’ve got ourselves and we need to enjoy the game, the occasion, playing here at home.
"Everyone has poured their heart and soul into this thing since we were sitting in this room last year.
"We wanted to be in the final last year but we didn’t get to that stage. Credit to Northampton, they beat us on the day. So we’re back here now and it’s about everyone delivering everything they possibly can.
"We know its going to be a serious test against a team that has also fought its way through to this point. Where would you rather be?"
Given how strong Bordeaux look, getting to and losing in a final to the defending champions wouldn't be as catastrophic as any of the last number of European defeats.
This one, however, similar to their last knock-out meeting in 2015, has a feel of one that's within their grasp. If the two teams come out and play to their potential then it's Leinster's to lose.
"It’s about letting go, attacking the game, having the courage to play the way we want to play and going for it completely," said captain Caelan Doris.
Losing is not an option for the hosts and that may drive them over the line.
Verdict: Leinster
Leinster: Hugo Keenan; Tommy O'Brien, Garry Ringrose, Robbie Henshaw, Rieko Ioane; Harry Byrne, Jamison Gibson-Park; Andrew Porter, Dan Sheehan, Tom Clarkson; Joe McCarthy, James Ryan; Jack Conan, Josh van der Flier, Caelan Doris (capt).
Replacements: Rónan Kelleher, Jerry Cahir, Rabah Slimani, Alex Soroka, Scott Penny, Luke McGrath, Sam Prendergast, Jamie Osborne.
Toulon: Melvyn Jaminet; Gaël Drean, Nacho Brex, Jérémy Sinzelle, Seta Tuicuvu; Tomas Albornoz, Ben White; Jean-Baptiste Gros, Teddy Baubigny, Kyle Sinckler; Corentin Mezou, David Ribbans; Junior Kpoku, Charles Ollivon, Mikheil Shioshvili.
Replacements: Gianmarco Lucchesi, Daniel Brennan, Beka Gigashvili, Matthias Halagahu, Zach Mercer, Baptiste Serin, Esteban Abadie, Mathis Ferte.
Referee: Luke Pearce (RFU)
Listen to the RTÉ Rugby podcast on Apple Podcasts, Spotify or wherever you get your podcasts, and email us at sportpodcasts@rte.ie
Follow our live blog on Leinster v Toulon in the Investec Champions Cup from 3pm on RTÉ.ie/sport and RTÉ News app and listen to Saturday Sport on RTÉ Radio 1
