Saracens' director of rugby Mark McCall has warned his players they will run out into a red-and-white-hot cauldron of noise and passion at 6.25pm on Saturday.
It's going to be an historic night at the all-new Ravenhill where the rebuilt main grandstand will be open for the first time.
Asked what he has told them to expect, McCall replied: "I just think it's important that you're not surprised by what you find. I'm well aware – and the players are well aware – of the atmosphere there's going to be on Saturday evening.
"It's going to be very different to what we find week to week. We played in front of 90,000 people at Wembley two weeks ago, but this is going to be more intense and more hostile.
"There's a difference between a corporate audience and a hungry rugby public.
"We've experienced that with that game at Thomond Park against Munster a couple of years ago, so hopefully the players won't be surprised by the atmosphere. I suppose our job is to turn that atmosphere into something different."
He insists his background as a former Ulster captain and coach is neither here nor there.
"For me, from a personal angle, it isn't very important – it's irrelevant," he says, straight-batting as impressively as his late father, Conn, who played cricket for Ireland in the 1960s.
"I've been delighted to see how Ulster have been doing over the last three or four years; they've made great strides and it's going to be exciting to see the new stadium," he continues. "But of course I am fully attached to this group of players at Saracens so the personal angle is not too important."
Asked for an update on Billy Vunipola, he knocks that one back to the figurative bowler.
"If you don't mind, I won't tell you whether or not Billy Vunipola will play. The people who have long-term injuries are Joel Tomkins, Alistair Hargreaves and Will Fraser."
Let's try from the far end; will his experience as a former Ulster coach help Saracens?
"No, I don't think so. Things have changed since then. It's not a relevant thing," is the deadpan reply.
He is more forthcoming when talking about Ulster.
"We've looked at them in great detail, as they will have done with us," he says. "They're an outstanding side, full of good rugby players and well coached.
"We understand that they're favourites for this game. They've billed it as the biggest game in their history. We know that we're going to be walking into a very different atmosphere than we're accustomed to."
They didn't look too hot at the weekend against Cardiff, though, did they? What did Saracens make of Ulster's 28-23 Arms Park defeat?
"We take that game with a pinch of salt," he replies. "We know that their mentality and performance levels will be completely different on Saturday. We're preparing for Ulster at their best rather than how they performed last weekend."
How pleased is he with Saracens' form?
"We've won 16 out of our 18 Premiership matches. We've been consistent throughout the season, but we know that we need to elevate our performance if we are to get a result at Ravenhill," is the cleverly-balanced reply – highlight your own pedigree whilst lauding your opponent. Touché.
He applies that format repeatedly.
Will last year's game have any bearing on this re-match?
"It's a different proposition going to Ravenhill than having a game at Twickenham," McCall reasons. "We know there is expectation on the Ulster team. Our job is to try and turn that expectation into pressure. That's not going to be straightforward because of how good Ulster are, but we'll do our best to make that happen. And if that can happen it gives us a chance."
Given how comprehensively Saracens won last year, is he expecting an Ulster backlash?
"If you remember last year a number of their players hadn't played that much before the game and that's never ideal," is McCall's response.
"I think Tommy Bowe came off the bench that day and you saw the difference he made in the 20 minutes he was on the pitch. They seem to have a really settled team at the moment, everybody seems to be fit and well, though I suppose they've got a decision to make on Stephen Ferris, whether he starts or comes off the bench.
"Other than that they look pretty formidable across the board – a very good side who are well coached and at full strength, so it's going to be difficult for us."
So what about the weight of expectation on the Aviva Premiership leaders?
"The history of the competition is that you need to earn your spurs. Ulster feel that they've done that; we're getting there. This is our third quarter-final in a row and we got through to a semi-final last year.
"So we think we're making progress, but at some point in time you've got to win one of these big games away.
"This will be a difficult one to win, but there is more expectation on Ulster than on us."