By the end of a calamitous Europa League exit even the intervention of a Video Assistant Referee couldn't prevent Scotland's champions taking a loaded gun and firing three bullets into their own feet.
Chasing their first victory in a UEFA knockout tie in 16 years the wait goes on after a 1-1 draw in Denmark raising expectations of a place in the last 16 of the Europa League.
Hopes were founded on the knowledge that, until this, no Danish side had even scored in Glasgow's east end, let alone won a game of football. On Thursday Copenhagen were gifted three shots on target and and scored all three.
A goal down after a Jozo Simunovic error gifted the Danish champions a critical away goal early in the second half, salvation beckoned with eleven minutes to play.
For two fleeting minutes Big Brother extended a helping hand in Celtic's direction, Odsonne Edouard defying a poor display to dink a Panenka penalty down the middle after VAR rightly stopped the play for a handball by Ragnar Sigurdsson Suddenly anything seemed possible.
Yet, just as the tide threatened to turn Celtic conceded within two minutes when Tom Rogic miscontrolled in the centre circle, Rasmus Falk bursting clear to roll Pep Biel into acres of space for the second goal.
In the final minutes Dame N'Doye danced through a ragged Celtic defence to add a third which was pretty much meaningless. It all felt horribly reminiscent at times of the Champions League defeat to Cluj in August.
Reluctant to criticise his players Neil Lennon admitted: 'The players will be hurting, so will the fans. I don't really think we need to analyse what went wrong. Everyone knows. It was basic individual mistakes - sometimes you can't legislate for that.
'I'm not going to throw anyone under a bus, we win as a team and lose as a team. I have a really talented bunch of players but we let ourselves down at key moments in the game.' Celtic will look back and reflect on a key three minutes early in the second half.
The first saw a Callum McGregor Celtic goal chalked off in dubious circumstances. The second saw Copenhagen seal the away goal they needed with their first chance of the game.
McGregor smashed a first time shot into the roof of the net from the edge of the area and the celebrations were painfully short-lived. Portuguese referee Artur Dias blew for an infringement when flapping, goalkeeper Karl-Johan Johnsson made the most of a bump with Christopher Julien in the area.
In a world of over-protected goalkeeper, replays showed there was nothing in it.
If Celtic were entitled to feel sore about that they could have no complaints over a calamitous Copenhagen opener in the 51st minute.
Since returning from injury Simunovic has developed a habit of giving supporters the fear. And the Croatian allowed a meat and drink long ball to bounce before playing a disasterously short pass back towards Fraser Forster.
An open invitation for the lurking, pressing substitute Michael Santos the wide man had time and space to pick out the lurking N'Doye in the centre. Christopher Julien did his best to smother the danger, the ball falling kindly for Santos to dink the ball into the net.
'I've not spoken to Jozo,' said Lennon later. 'I have a duty of care to him, he has come back from a long term injury, Yes, he made a mistake but we recovered and he didn't make a mistake for the second goal.
'If I need to pick him up, I will. That's my job.
'He has been magnificent for me since I came in the door. He's made a mistake, he's held his hands up and we move on.' The first goal was central to everything which unfolded in the end. In the first half Celtic had all the best of the chances. Yet where Edouard looked liable to score at will in the Parken Stadium the Frenchman couldn't get going here.
Despite his recent lack of game time Mohammed Elyounoussi - starting in place of on-form Leigh Griffiths - carried menace on the left. And the Norwegian crafted - and missed - a wonderful opportunity when he left Carlos Zeca for dead on the left touchline, making ground until the overlapping to hold the ball up for the overlapping Tom Rogic.
A poor clearance from the Australian's cross fell straight at Elyounoussi's feet and he blazed a first time effort high over the bar from 14 yards.. Falling to his knees he knew - as did everyone - what a chance it was.
What joy Celtic had came on the left flank. After half an hour Greg Taylor's cross was headed against Tom Rogic by the diving clearance of Mikkel Kaufmann, the ball striking the base of the post and bouncing to safety.
After a cagey start Celtic worked up a head of steam before half-time. The loss of left back Mikkel Kaufmann for Michael Santos before half-time forced Copenhagen to make their first change of the night. Early in the second half it would prove a decisive development.
Celtic will reflect ruefully on those opening six minutes as sliding doors stuff. The disallowed goal might have changed the narrative. An accident waiting to happen, the shaky defending of Simunovic for the opener offered no guarantees.
With 20 minutes left to play Lennon had nothing left to lose. Throwing on Griffiths for Elyounoussi the Scotland international's first contribution was to fire a snap first time shot straight at Johnsson from 12 yards with the keeper lying on the ground.
The penalty - rightly awarded where Sigurdsson handled in the area - threw Celtic a lifeline which proved painfully a mirage. Edouard took it brilliantly and it felt like a get out of jail card.
Yet in those final stages Copenhagen looked fresher, fitter and stronger. Celtic looked leggy.
The visitors had men left over when Rogic lost possession in the middle of the pitch and the impressive Falk sent Pep Bilel in for the killer second. N'Doye's goal in the final minutes was academic. After a series of confident, impressive performances in the Europa League Celtic picked a bad night to fall to bits.