Neil Lennon asked several things of his squad following the bitterly disappointing defeat at Ibrox on Sunday.
The response came in the form of a 2-0 Scottish Communities League Cup victory in dreich Dingwall against a Ross County side already boosted by a history of slaying this particular giant.
However, Lennon today revealed he had already received the answers he wanted before he set off for the Highlands.
The debrief which followed the weekend Old Firm defeat included a full and frank exchange of views when the players were not only required to listen to the management team's brutal opinion on what went so badly wrong in the second half, but encouraged to offer their own views on why they collapsed in such dramatic fashion.
The result was there for all to see last night as the first step on the road to redemption was taken. The news of the exits of Rangers and Hearts, relayed to the players as they boarded the coach for the short journey to Inverness airport and the flight home, simply sealed a good night's work.
But the roots of this were planted at Lennoxtown on the days between losing to Rangers and running out at claustrophobia, rain-sodden Victoria Park.
The green shoots of recovery must now be carefully cultivated, though Lennon acknowledges that all in the garden is not rosy simply because they got back on the winning trail.
Reflecting on the see-saw few days, Lennon said: "I wanted to see a reaction, and a good reaction. I got what I was looking for. We had words on Sunday and Monday. I want the players to forget about that now, though it will be difficult for me to forget about it. It was a two-way conversation.
"But I think they know, in the main, that they let themselves down badly."
The sting was taken out of any possibility Ross County could add to Celtic's woes when Joe Ledley's header from an Anthony Stokes chip was bundled over the line from close range by Gary Hooper with only 13 minutes gone.
Lennon appreciated the early strike, but is not convinced it was what saw them safe on what could have been a testing night.
He said: "I think we set the tone just with the way we approached the game, so that was pleasing. Our attitude, our work rate, the pace that we played at, the 50-50s, the aerial challenges.
"All the things that were not there on Sunday were there last night. I hope they use that memory as a reminder of what can happen if you don't do the basics of the game well."
The alien environment, offering several of the team a first taste of a little community ground with the crowd on top of you, and on a night when the downpour refused to relent, could have been a cue for some to take a rain check.
But the five changes to the side from the weekend, some through injury and suspension, others through choice, culminated in a performance that oozed purpose and determination. From trackside, Lennon made sure they never forgot what was expected, and his constant coercion was rewarded.
"It wasn't easy," he added. "It never is coming to a First Division ground. The conditions were difficult to play on, but it was a very professional performance. The football we played at times in the final third was very good. I was also pleased with the clean sheet.
"That was very important to us. There were some very good individual performances."
When Scott Boyd was hustled into turning a Stokes cross into his own net five minutes after the break, Celtic's name was as good as in today's quarter-final draw.
Not even the Achilles' injury which forced Kelvin Wilson off at the interval could upset Celtic, Charlie Mulgrew looking even more comfortable and assured when he stepped back to partner the reinstated and re-energised Daniel Majstorovic.
Mulgrew took responsibility for organising the defensive line, and the fallibility and fragility of the weekend seemed like a distant memory.
Only former Celt Michael Gardyne gave them anything to worry about when, after Wilson and Majstorovic both went for the same high ball and succeeded only in combining to head it straight to the County midfielder, he volleyed a shot which cannoned back off a post.
The pity is that Mulgrew is suspended for Saturday's SPL game against Inverness, while Kelvin Wilson is already doubtful, so even more reshuffling will have to be done at the back.
But at least the team is now heading back in the right direction after defeats in Madrid and Ibrox.
Lennon, though, accepts it is only one small step, and said: "We know there will be more difficult games coming up, but they should get a little lift out of that. I am not saying we've turned the corner. But, I'm talking about 45 minutes at Ibrox where really, in a big game, it was very disappointing.
"But the mental strength of the players is there. I've no doubt about that."
TIMES TALKER: Is Celtic's name on the trophy?
CLEAR RUN NOW says RONNIE CULLY
After the shocks which have already been recorded in the first three rounds, today's Scottish Communities League Cup quarter-final draw holds little fear for Neil Lennon's side.
With so many serious rivals for the trophy already out, the door is wide open for Celtic to get their hands on the first piece of silverware available this season.
Of course, given the inconsistency of results they have had this season, it would be foolish to put your mortgage on the Hoops, especially at the skinny odds now on offer from the bookies.
Rangers' early exit will put extra pressure on Celtic to make sure there are no slip-ups in the 270 minutes that stand between them and lifting the cup.
But, even with the SPL title the priority, and an interest in the Europa League, there is more than enough strength in depth at Parkhead to target winning the League Cup.
NOT CERTAIN says MATTHEW LINDSAY
Celtic progressed to the last eight with a highly-professional defeat of Ross County.
And, with Rangers and Hearts both being knocked out of the competition, the Parkhead club is now being hotly tipped to triumph.
But results this week have shown that nothing can be taken for granted, and it is no given that the Hoops will land this prized piece of silverware.
East Fife humbled Aberdeen at Pittodrie on Tuesday and last night Ayr defeated Hearts while Falkirk stunned holders Rangers.
Neil Lennon's players, who slumped to a 1-0 defeat at home to St Johnstone earlier this season, would do well not to take anything for granted.
They showed against the Gers at Ibrox on Sunday they are more than capable of having bad days at the office as well.
Nothing less than a top-drawer performance in the next round, and in the remaining fixtures after that, will suffice for the Glasgow giants.