Trimble: It feels like you've been in a car crash
Every second counts as Ireland prepare for another onslaught
Every second counts. And every second is counted.
The time-keeper is in control far above the action. He starts the clock. The seconds ebb away. He stops the clock. Time is momentarily stalled, breaths revived, muscles temporarily restored. Then he starts it again. And it ticks. And it ticks.
Take last Sunday, for example. The opening play. Dan Biggar collects. Dan Biggar is smashed. One of the game's influential figures is, despite his bravery in trying to linger, effectively removed from the contest.
In just one second. There will be 4,800 of them today. Potentially 4,800 events that can turn a game in, well, a second.
Against France, the weather may dictate patterns but there will still be scatterings of seconds which will prove pivotal to this encounter.
Today, particularly with Guy Noves' renewed commitment to empowering his players to play what's in front of them, even if it means they have no idea what might be going on behind them.
Against Italy, they tried 19 off-loads but half were turned over; there's 19 seconds of action right there, each of them capable of sweeping the French into an attacking position against an unsettled defence.
Or, alternatively, allowing the opposition to steal and launch a counter of their own against a side prepared for attack but suddenly resorting to last-gasp defence. It may take just one to launch a decisive, game-changing impact.
But how to decide when to seize the precise moment with merely a second's notice?
"You just imagine what Joe's going to say to you in the meeting the following day," smiles Andrew Trimble, a key plank of Ireland's brains trust at these crucial moments, in both defence and attack.
"In terms of not getting sucked into their type of game, I think there's times when you want to up the tempo and especially with a big, heavy French pack.
"It's an instinct thing but it's an instinct that's been trained into you.
"From my point of view it's based on playing for 10 to 12 years and still not getting stuff right, you just hope you get more right than wrong or you'll hear about it."
The fractured build-up hasn't helped, for all that Joe Schmidt's side, the best drilled in the northern hemisphere, will resort to basics in an attempt to defy French chaos with rudimentary structure.
"Adrenaline may have to drive us on in the final minutes," Trimble (left) concedes. "That has the potential to be the case.
"That game against Wales, maybe because I hadn't been involved in a while, it feels like you've been in a car crash.
"My shoulder was hanging off me, everything else is just wrecked and you're looking around - the backs took the brunt of it for some reason, a lot of the guys were struggling with knocks and bangs.
"But I feel infinitely better than I did two days ago so you do bounce back through the recovery protocols.
"Ice baths, recovery skins, diet and everything, it's unpleasant for a couple of days but you feel better as a result.
"Being in Paris and the excitement when we were there two years ago and the potential for that to happen again is going to be something that really drives us on."