Of all the fixtures on Andy Farrell's schedule, this one matters the most.
It's personal for the former England international who once felt the breadth of 80,000 fans singing 'The Chariot' on his neck, the coach who was part of the disastrous Twickenham defeats at the 2015 World Cup and shown the door afterwards and the father whose son captains the opposition who have lorded it over his team in the last three meetings between the teams.
In public, the hard-nosed professional will stick to the script and focus on the process but inside he must be desperate to see his team perform today.
The reality is, even their best may not be enough against a team that has more experience, greater cohesion, more power and better half-backs than the men in green.
All week, Eddie Jones, John Mitchell and Matt Proudfoot have been stoking the fires, talking about Ireland's "dominant" performance against Wales.
But, like Leinster or Munster stepping up from the PRO14 to the white heat of facing the European elite, facing England is a very different ball-game.
The stadium may be empty, but England's relentless and remorseless pressure game will engulf Farrell's men if they get on top.
Unlike the Saracens team that won in Dublin in September, this England team is capable of an 80-minute performance and they were annoyed back in February when they let Ireland back in.
Wins in Twickenham are prized treasures in Irish rugby history and, while there's a couple of smash and grab raids in the collection, they're largely secured by strong teams on top of their game.
Ireland's are missing several key men, while Farrell has been brave with his selection by leaving Jacob Stockdale, Conor Murray and Iain Henderson on the bench with less experienced men starting.
He has a new captain and a rookie half-back pairing, a back three who have never played together before and a bench that looks lightweight in comparison to England's.
In previous matches, Jones' men have smashed Ireland in the contact zone, depowered their set-piece and pulled them apart in the back-field. They've forced uncharacteristic errors and undermined Ireland's confidence.
In February, Ireland tried to meet fire with fire but Maro Itoje took it all in his stride.
England expect physicality, but if Ireland go chasing it they'll be dashed on the rocks of the home side's power game.
"They've gone for a big back-row and a big back-five," defence coach Mitchell said. "They obviously want to play a power game and take us on, which is great. We can't wait.
"They've selected a big pack. They have a running No 9 and a 10 who likes to play long side and short side and who has a fairly handy kicking game. The wingers of course can penetrate in close.
"They have a number of options so we're expecting a bit of variety from them, but they're obviously looking to create a platform and stop our momentum."
If Ireland can do that successfully, they'll be on to a winner.
If the forwards can give Jamison Gibson-Park and Ross Byrne the platform to play and they can get Bundee Aki and Chris Farrell over the gainline, then they'll have a chance to pull something off.
But everywhere you look, England have the greater threats.
Their scrum is ferocious, their back-row is dynamic and mean, their half-backs are full of experience and, while their backline is missing Manu Tuilagi it still has plenty of threat.
At this stage of their development and in the context of this one-off tournament, Ireland just need to fire some shots and stay in the game. If they don't things could get ugly and it may be another long day for their coach.
Verdict: England 31-10 Ireland