It disappeared in the floodlit haze of a Spanish night as a ball flashed across goal and Kris Boyd, the master of converting the penalty-box chance, failed to make a connection.
It was March 2006 and Alex McLeish, the Rangers manager, was condemned to watch his team lose on away goals to Villarreal after the Ibrox side had become the first Scottish team to qualify for the knockout stage of the revamped Champions League. A 2-2 draw at Ibrox was followed by a 1-1 scoreline in Spain where Boyd could only stand flat-footed as the chance to make history presented itself.
"My life passed before my eyes when the ball flashed across the box and Boydy just never quite got his timing right, which wasn't like him," said McLeish. "But for that, we would have probably been in the next phase."
There is a moment when he pauses to reflect on what might have been before adding: "You have to look forward and accept it was just one of those things. There were other times when we had that bit of luck. That's the rub of the green.
"Did I speak to Boydy about it afterwards? No. When a guy has scored as many goals as he did for the club – and normally takes seven or eight out any 10 chances – you just have to move on."
McLeish, of course, moved on to a career as manager of Birmingham City and Aston Villa and now awaits another opening, preferably in England although he could be tempted to work abroad.
The events that evening in Spain, though, served to emphasise how narrow the margins are when the big prizes are at stake. "At the very top level, you might only get one chance. If you don't take it then it can be costly," he said.
This reality, he believes, may favour Neil Lennon's side who are in the draw for the last 16 that takes place on Thursday. "Celtic seemed to convert a lot of their chances in the group stage and took advantage of everything," said McLeish.
The former Scotland manager said Celtic had exploited the options offered by Georgios Samaras, particularly by playing the long pass. "They could put it up there knowing there is a good chance this guy will keep the ball alive. He did that in the last match and got the penalty. Barcelona wouldn't have launched that ball forward because they don't have that type of player. But it is about playing to your strengths and maximising your resources. Celtic have done that superbly."
McLeish does not rule out the chances of Celtic progressing to the last eight of the Champions League despite having to face one of Manchester United, Juventus, Paris St Germain, Malaga, Borussia Dortmund, Bayern Munich and Schalke. "If they have their strongest team at Celtic Park then no-one is going to be safe there," he said. "People might have felt Celtic would lose matches at home but they have been tactically very astute. The fans always want to drive them on and maybe go a bit gung-ho, but tactically they have done really well in that competition. Neil Lennon and his coaches deserve immense credit."
McLeish also ponders a ''might have been" when talking about Ryan Fraser, the 18-year-old Aberdeen winger who sees his future away from the north east. McLeish spent a stellar 18 years at Pittodrie but was courted by a series of clubs, most persistently by Tottenham Hotspur.
"People ask if I regret not going down south and, while I look back and say I never regret anything, I do always wonder," said the former centre-half, who won 77 caps for Scotland and 12 trophies for Aberdeen, including five Scottish league titles and the European Cup-Winners' Cup. "I was with a great Aberdeen team and it was great going in every season knowing you had a chance of winning something. But there was no Bosman, no free transfers; even at the end of your contract the club still had a hold," said McLeish.
He added that Steve Archibald, his former team mate at Pittodrie who had signed for Spurs, would call every time the defender's contract was coming to an end to tell him that Terry Venables wanted him at White Hart Lane.
McLeish stayed where he was but said Fraser, who has turned down the offer of an extended contract at Aberdeen, was old enough to make his own decision. He pointed out that his son, John, worked for the agency representing Fraser, but emphasised McLeish Jr was not the player's agent.
He added: "I'm not here to say what Ryan Fraser should do. He's still a young man learning his trade. If he's good enough he's old enough. From the highlights I've seen he looks an exceptional talent. He's a pocket dynamo but I don't think he's just about pace. From what I've seen he's a clever footballer as well, looks to link in with the strikers. There's more than one dynamic to his game, rather than just being a winger who accelerates past people. He's got a wee bit of nous to his game."
He said Joe Harper, the Aberdeen legend, had told him that Fraser had more than a chance of making it in the game. And Harper, like Boyd, knows all about chances, missed and taken.