'When it matters most, this Ireland team have come up with big performances' - Paul McGrath
We are just hours away from the biggest sporting event of the year. Will Martin O'Neill's Ireland be on a plane to Russia next summer?
Here are some of the experts' views.
The second leg of this World Cup play-off in Dublin has to be a better spectacle than the game we saw in Copenhagen on Saturday and while most people suggest a more open game might play into Denmark's hands, that might not be the case.
When it matters most, this Ireland team have come up with big performances and if you look back to the home game against Germany, the play-off win against Bosnia to qualify for Euro 2016 and the win against Italy in that tournament, we have shown we can rise to the occasions.
We shouldn't doubt ourselves and from what we saw from the Danes on Saturday, they don't have too much to frighten us so long as we stand firm at the back and show a little more ambition going forward.
I'm already nervous thinking, but the players should see that as an opportunity rather than a daunting challenge. If they look at it in that positive way, they can come out on top.
MCGRATH'S VERDICT: Ireland 2 Denmark 1
Let's all pretend the game in Denmark on Saturday didn't happen and hope that what we see tonight's will produce one of those golden Ireland moments.
I was disappointed by the performance we put in on Saturday because our players seemed to be scared to hold on to the ball and we were happy to settle for the 0-0 draw.
It was a decent result amid a poor performance, but there is a danger that the lack of ambition we showed in Copenhagen will come back to haunt us tonight, especially if Denmark score first and get that vital away goal.
If they do open the scoring, the Ireland players have to stay calm and believe they can get the two goals they would then need to progress and I also hope we show a little more belief and composure on the ball because we have some good players in this Ireland team and they show that every week in the Premier League.
It's going to be tight, tense, horrible to watch as a spectacle and for our nerves, but let's not worry about how we get through so long as we find a way to do it.
ALDO'S VERDICT: Ireland 1 Denmark 0
The huge significance of the away goals rule means the 0-0 draw in Copenhagen on Saturday was a dangerous result for Ireland.
Boss Martin O'Neill suggested his side will probably have to score twice to secure a prized place at Russia 2018 and recent history suggests we will struggle to do that in front of passionate Irish fans at the Aviva Stadium.
We have to hope that our players will embrace the moment, rise to the challenge and play with the kind of verve we have seen on only a few occasions in the O'Neill era, but that script is unlikely to be played out tonight.
Instead, we are set for another 90 (and possibly 120) minutes of pretty dire football, but the glittering prize up for grabs means that on this occasion, another poor performance will be overlooked if the Aviva Stadium is toasting a famous Ireland win.
Scoring first is crucial to Ireland's hopes and they need Robbie Brady's set piece delivery to improve for that to come to pass, but Denmark have better technical players and they should shine if the game opens up.
All of us want to be writing about a famous Irish triumph at around 10pm tonight, but I fear it might be a tale of heroic failure.
PALMER'S VERDICT: Ireland 0 Denmark 1