Every Old Firm game has a story, with several sub-plots attached to it.
Like all good scripts, today’s fixture is yet another that is hard to predict how it will end.
Earlier this month, I tipped Celtic to win the Betfred Cup. But I didn’t imagine that Rangers would dominate pretty much all of the match and still leave Hampden without the trophy.
Steven Gerrard and his players would have been down after that defeat.
But they have bounced back to win every Premiership fixture since, and also reached the last 32 of the Europa League.
They still find themselves trailing their great rivals by five points going into this game, albeit they have a game in hand.
So there is no doubt the onus is on Rangers to win this match.
A draw suits Celtic. A win for Neil Lennon’s team and nine-in-a-row is as good as in the bag.
The Parkhead club will go into today full of confidence, and that is understandable with the quality they have in their team.
They also have home advantage, which gives them 58,000 of their supporters inside the stadium, while the visitors have only 800.
However, I think Rangers will fancy their chances.
One of the sub-plots is the Alfredo Morelos versus Fraser Forster battle.
The big Celtic keeper had the game of his life in the Cup Final at Hampden, and left Morelos a broken man.
But the Colombian has recovered quickly and scored in every game he has played in since then.
So can Forster produce such an outstanding display today?
Will Morelos be as hesitant if he is presented with an opportunity?
In games against Celtic in the past couple of years, the Rangers talisman has missed five or six golden chances, ones that strikers dream about.
He has to score in this fixture at some point – and it may well be this afternoon.
That said, one goal may not be enough to beat Celtic at home. Rangers could very easily require two.
Celtic are formidable on their patch, and have produced some breathtaking football and brilliant results.
Scott Brown will lead by example and protect his defence.
From middle to front, they have wonderful talents in Odsonne Edouard, Ryan Christie, James Forrest and Callum McGregor.
All four are potential matchwinners.
Neil Lennon would love to be eight points clear by 2.30pm.
That would send him into the winter break feeling relaxed, and confident of what his team could achieve in the second half of the campaign.
As I said, a draw is a more than decent result for Neil. But he is not the type of manager to ask his players to settle for a point.
No, he will demand all three.
Another contest to keep an eye on will be Ryan Kent against Jeremie Frimpong.
Frimpong has lit up the Hoops in the past couple of months and brought a fresh enthusiasm and attacking dimension to the team. He is a fine young talent.
But, first and foremost, his job is to defend and he needs to be more aware of that.
He was red-carded at Hampden in the Final, but wasn’t held accountable as his team-mates won the game and they all went home happy.
Kent scored at Parkhead last season and will want to produce the goods again.
He is a talented footballer and he will need to be on form if his team is to leave Glasgow’s East End with the three points.
Kent needs to subdue Frimpong, and keep the teenager on the back foot. That, however, will be easier said than done.
Rangers haven’t won an Old Firm clash this season, and that is something they need to rectify as quickly as possible if they are to win the title.
All in all, I wish both teams well, and hope they produce an exciting and entertaining 90 minutes for Scottish football.
This game will be beamed all over the world, and the interest in it is as huge as ever.
Whatever happens, both managers can be proud of their achievements in the first half of the season.
Steven Gerrard inherited Rangers when they were heading towards an abyss.
But in just over 18 months, he has turned them into a proper force again and a credible football team.
They are in the hunt for silverware and performing well in Europe. He can hold his head high.
The same applies to Neil Lennon.
He took over back in February when Brendan Rodgers left for Leicester City, and there was a lot of resentment around Celtic Park over the timing of his departure.
That seemed to take up a lot of focus and energy for the Celtic supporters, and it would have been easy for the football club to take its eye off the ball.
But they appointed the right man in Neil to succeed Brendan, and he kept a sense of clam around the place and made sure they got their business done to steer the Hoops to a treble Treble.
Neil has enjoyed an outstanding 2019, and will be doing everything to make sure it ends on the most positive of notes.