George Hook: Are the Irish provinces up for the fight in European competition?
One of the most famous battles in history took place in a narrow pass in Thermopylae in 480BC, when 300 Spartans stood bravely against the might of the Persian army.
Over four days, in a small gate that was no more than 20 yards wide, the great Spartan King Leonidas led his men in one of the greatest feats of heroism the world has ever known.
Theirs was a brave but futile stand, for the Persian army was too vast to be withstood by a mere 300 men.
On Sunday, Leinster's own King Leo will lead his army into battle against a far superior force in Toulon. The result, like in Thermopylae, is a foregone conclusion; Leinster will lose and what remains of their European Champions Cup ambitions will be ruthlessly quashed for another season.
Munster, on the back of a hopelessly flat performance against the Dragons, host the ever-dangerous Leicester Tigers.
And Ulster, with key personnel missing, hope to revive their campaign against another French force, Toulouse.
This is a defining weekend for the Irish provinces. And all the signs point to a bloodbath of foreign victories.
Let's start with Leinster's kamikaze mission in Toulon. Ignore the minor blot on the Toulon copy-book. Wasps are a better side than most of us - myself included - gave them credit for at the beginning of the season. And Toulon's paltry performance in Coventry can be scratched down as a one-off.
The three-time European champions have since dismantled Clermont Auvergne 35-9 in an away match in the Top 14, before putting 53 points on Agen at home last weekend.
That last European defeat will focus Toulon minds. They cannot afford another slip-up. I expect ruthless savagery by the defending champions.
What can Leinster offer in response? We will learn more about Leo Cullen's thinking when his team selection is revealed this afternoon, but one would hope that youth and talent will trump experience and predictability in his starting XV.
Luke McGrath must start at scrum half. Garry Ringrose should also get a chance - at the very least he deserves a spot on the bench. And why not give Josh van der Flier a go in the back row? At this stage, Leinster have nothing to lose.
By the way, I expect Toulon to target Jonathon Sexton, who has not been the same player since his three-month concussion break last season.
Leinster fans, prepare yourselves. This one will make for uncomfortable viewing.
No doubt Munster fans are relying on their team to pull out the usual European heroics against Leicester tomorrow, even though last Sunday's performance in Newport was nothing short of abysmal.
From butchered chances, to dropped passes and a lazy, uninterested approach in defence, Munster were all over the place against the Dragons.
That it was a largely second-string team is of little comfort. Performances begin with the right attitude and Anthony Foley must have been furious by what he saw from his side in Wales.
In years past, Munster had natural leaders to turn the tide in times of crisis. But tomorrow evening, there won't be a Paul O'Connell, or a Ronan O'Gara or a David Wallace to rally the troops.
O'Connell's natural replacement, Peter O'Mahony, is sidelined with a long-term injury. Conor Murray has barely laced up a boot in three weeks.
Will a capacity Thomond Park crowd galvanise the team to a better performance?
I'm not so sure. Leicester come into this game on the back of four successive victories. They have been beaten only once in the Aviva Premiership all season.
Tonight Ulster hope to salvage what slim hope remains of their European ambitions. Toulouse can be flaky away from home, as they showed at Saracens in round one, but it would be dangerous and foolish to just presume that they will not turn up.
Ulster also have to manage without Tommy Bowe and Iain Henderson.
History advises against writing off the Irish provinces ahead of big European weekends. But there is an altogether different feel to this one.
Perhaps Ireland's best chance of a place in the knockout stage rests with Munster, but a defeat tomorrow would make their task of qualifying almost impossible.
Time was, Irish provinces were up for the fight in European competition, regardless of the opposition. Can we say the same about the current crop? It could be a long and uncomfortable weekend ahead.