THIS is a tale of father and son and it begins at the McGeady family home on the southside of Glasgow and with a video tape that in 10 minutes tells you so much about the making of Aiden McGeady.
It was filmed in the early 1990s when he was eight, when he sat before the camera of aspiring film-maker and friend of his dad's, Malcolm McKissock, and spoke about his life's dream, how he would like to play for Celtic (and then for Liverpool), how he loves John Collins and Pierre van Hooijdonk (because they take great free-kicks) and how great his dad is (because he's there all the time and watches him play).
There is glorious footage of the boy performing on a red dirt track in the Gorbals, a slow motion film of him weaving his way through the traffic of a seven-a-side game for the Govanhill Cubs, a slaloming run and a thing of beauty that finishes with him rolling his foot over the top of the ball to deceive the goalkeeper before calmly passing into an empty goal.
Then there is John, the father. John is on the film, too. But he's not looking to the promise of tomorrow like Aiden. He's thinking about the what-might-have-beens of his past. He's talking about his own time in football, his departure to Sheffield United at 16, his terrible homesickness, his five years as a winger and his injuries that left him with a busted knee-cap and a broken career in his mid-20s. Mostly, he is talking about his father, about the problems they had, about the lack of interest he displayed in John's own football life. When you connect it to the close bond between himself and Aiden, the poignancy and relevance of it is obvious.
From a distance John might appear as another example of a man trying to live his life through the glory of his son's success. No doubt people have said that at some stage but that is not the case. All he's tried to do is steer his boy clear of the problems he himself encountered.
John switches off the video tape and talks about his old man. "Until about five years before his death I never really spent much time with him," he says. "Himself and my mum were raised within a few minutes of each other in Gweedore in County Donegal and my father was a typical product of his generation. He was a tough boy, not given to sentiment. He didn't really take an interest in my football, didn't really understand the game to be honest. Years later I found out that when he was down the pub having a few pints with his mates he'd talk about me, he'd tell the lads how I was getting on. I never knew this. He'd talk about me rather than to me. He was probably no different to many other fathers in those days."
Is it any wonder that John has been there every step of the way for his own boy? Hardly.
The sense of pride in his son's career is huge. Last weekend John visited his mother in Donegal. The family went down to the local hotel to watch Celtic play Aberdeen and they smiled their way through Aiden's performance. He has never played better, Gordon Strachan said as much. This week he will face a bigger and better challenge when Barcelona arrive in Glasgow. Word has it that Aiden is more than a little excited at the prospect.
John tells you they've had some right barneys in this very room we're sitting in. "I'm very honest in assessing his performances. Always have been.
"We go through it after every game and I don't go easy on him because I don't think that's the right thing to do. He's not going to do everything right in every game so what's the point in pretending. Oh, we've had some discussions, put it that way."
Theirs has been a hell of a journey. He tells you all about the interest from down south, the expeditions to the top clubs in England for trial matches, Liam Brady's pursuit of his signature for Arsenal and the disbelieving words of other youth team coaches. There was one time at Everton when a development officer from Goodison Park invited McGeady down for a game, prefacing the invite with some caution. 'Your boy will have to be very good to get a look-in because we've got the best here'.
The guy started talking about an 11-year-old on Everton's books. This kid was special. That day at the trial McGeady played in the same side with a young man that John feels sure was Wayne Rooney. And McGeady excelled, just as he did pretty much everywhere he went.
These were promising days in the young life of John and Elaine McGeady's son but domestically things were tough. A little while before John had hit the wall as regards working on the buildings, the allure of digging holes and laying slabs and pouring concrete having worn off after seven or eight years of that hard life; John was a restless spirit. 'What do you want to do?' Elaine asked. 'I'd love to teach,' John replied. So he did. He went to university and became an English teacher.
"I'm 49 now and I've been teaching for 10 years and I love it. But in the beginning it was hard going financially. We were living in this house and we had a substantial mortgage and kids. Some nights I'd be sitting here with my head in my hands worrying about how we'd survive the following week. A former teammate of mine, Gary Hamson, who is now Aiden's agent, rang me one day and said, 'look, you're entitled to a retraining grant from the PFA, and sure enough I got a cheque in the post for 2,500 and that made a hell of a difference.
"Around this time loads of clubs wanted Aiden but I was determined that he wasn't going to England. I remember what I was like down there at the start and Aiden would have been the same. At such a young age he'd have missed home as much as I had.
"Clubs made offers, not overtly, not a promise of a briefcase full of money but overtures were made from certain places that would have sorted out our financial plight at the time. But that was never going to happen. Just as long as we got by and kept the house we were fine. Aiden was always going to stay in Scotland."
The crunch came on an afternoon in Blackburn. Another day, another trial, another pressure game for the young man. This time McGeady failed to live up to expectation.
'How did I do, dad?' he asked
'Well, you didn't cover yourself in glory, son. You didn't get much of the ball but when you got it you didn't do a lot with it.'
The conversation developed. Decision time was at hand. 'Are you happy going to these trials, Aiden?'
'Well, I feel under pressure all the time… '
'I don't think it's fair on you. I think it's too much. Do you know what you want to do.'
'Yes, dad, I want to sign for Celtic.'
The deal was done in a day. Celtic had the player they coveted for years and McGeady had a stable footballing environment he could flourish in. And how he has flourished. It hasn't been a bed of roses for him but he's worked his way through it. There was a time, pretty early in Strachan's new era, when you thought that McGeady was going to be one of his victims, one of those faces that just didn't fit. He was dropped, there was talk of him leaving, there was even more talk of Strachan being especially hard on him and now there is just sweetness and light and glowing tributes from the manager about performances so good that Strachan feels McGeady will be showing the DVDs to his grandchildren in time.
There's been worshipping at Celtic Park but abuse away from it. This is the downside, much of it traced back to his decision to declare his international allegiance to the Republic of Ireland. John remembers a friend phoning and warning him about the possible ramifications.
"Aiden was only 15 at the time but we knew there'd be stick down the line. We just didn't realise how much stick. I mean, to hear your son being called a traitor is a little hard to take.
"To be fair, it was a lot harder a year ago than it is now but those people who abused him that way didn't know the family history. Look at the video again. He's eight and look at the top he's wearing. It's an Ireland top. He absolutely loves Scotland but this thing goes deep. It wasn't him being opportunistic but some people won't believe me when I say that."
Has it bothered Aiden? A little, for sure. But he's got broad shoulders for a young man and has an amount of inner-confidence, "much, much more than I had when I was player," says John. "I got very nervous before games. He doesn't.
"He just revels in it, the same as he did when he was out on the road there doing keepy-uppy with tennis balls and golf balls and annoying the neighbours."
John says he used to go to an upstairs bedroom to see how his boy was doing. Now the view is shared by 60,000 others, all hoping and praying that a little more McGeady magic on Wednesday will lead to another one of those heady, heady Parkhead nights.