Picture the scene: playing out is a cup match that embodies a bitter, 40-year-old rivalry over which blood has been spilt and enemies forged in the annals of footballing history. Decades of hatred, malicious vitriol and vilification have led to two sets of loyal fans forming a permanent bond of contempt for one another; the kind passed down from parent to child before anything else has the chance.
This is a night as bitter as the rivalry itself, but the south coast isn't braced for cold; instead, it's ready for warfare. Having only played out once in the past five years - an inconclusive goalless draw - huge amounts rest on who wins and who loses in this most personal of competitions. A hero steps up: the man who has traversed the divide between these two foes and has lived to tell the tale.
Picture the scene when that man controversially nets the winning goal to secure bragging rights for his current club and assure shame and heartbreak for his former.
Well, no, picture it again.
This game is so boring that Ian Darke is spending the entire game talking about what VAR might do if something exciting actually happened. #cpfc— Five Year Plan (@FYPFanzine) January 8, 2018
For all you would have expected the so-called M23 derby - Brighton and Hove Albion against Crystal Palace - to have been the rip-roaring battle of honour that we've described above; the night itself however was a fairly tame one.
Palace fans gathered and drank throughout Brighton's centre and faced little or no confrontation at all. Players were cautious and reserved in their challenges, with only one card brandished. And once Glenn Murray - our aforementioned hero of the hour - had settled it to give Brighton the 2-1 victory, everyone seemed to get on with their evening.
Neutrals ridiculed and mocked this supposedly heated enmity whilst Falmer Stadium had a crowd of less than 50% of its potential capacity. The night was privy to the embarrassing sight of Sussex Police officers outnumbering the inoffensive crowd of Eagles they were marshalling through the streets of Brighton and, overall, things felt a bit subdued.
So just what happened to this once flaming grudge-match?
Before we answer that, we need to look through its rich history first.
Brighton/Palace was a rivalry formed slap bang in the middle of the 1970s. In '75/76, the two southern clubs were battling for promotion to the Second Division. As neither club succeeded, this battle continued into '76/77, when the pair faced off five times in one season. None of these quintet of game were pretty.
At the close of one FA Cup replay match, Brighton were forced to re-take a penalty which they subsequently missed and lost the game as a result. The Seagulls' gaffer, Alan Mullery, went berserk: shouting abuse at Palace fans, confronting the ref and making a general fool of himself in front of thousands of people.
From that day on, the rivalry has been intense and wholeheartedly endorsed by both sets of fans.
Something had changed come Monday's cup game. When Palace visited the coast for the first instance this season - the first time the M23 derby had been played since the Eagles knocked the Seagulls out of the Championship play-offs in 2013 - it was for a league game which saw hoards of fans kept from entering the stadium and a statement from Sussex Police weeks later admitting to pedalling several lies regarding Palace's behaviour.
On a train back to Brighton.— Chris Russell (@RusselI2103) November 28, 2017
Didn’t watch a single minute of football and have spent two hours being treated like a criminal!
Utter disgrace pic.twitter.com/IAD6QH8nss
The whole affair looked as if it was stoking the fire of this historic rivalry and when Palace drew Brighton from the velvet bag only days later, things looked set for a fierce, heated exchange.
For those from the era, memories of the '76/77 season flooded back. After all, cup games were the cause of their contention in the first place and the two sides now had a real excuse for getting their own back.
Sadly, the actions of the police on that fated night had led to many fans feeling put off from the whole thing entirely. Palace were only given a measly 2000 tickets and the game was scheduled for an evening kick-off on a Monday night. Not exactly the recipe for battle.
So, when it came to it, Brighton's Falmer Stadium looked much like the sort of sparse and speckled turn-out expected at a development squad's game. From afar, the blue plastic of the ground's seats stood out more than the odd black interruption of a loyal fan's winter coat.
With Palace employing a depleted, injury-stricken squad, most south Londoners were relieved to avoid any more unnecessary matches and focus on that all-important goal of staying up. A trip to Middlesbrough, it would seem, was not a trip worth bragging rights.
Hopefully, Palace/Brighton isn't a rivalry that has burned out entirely. Two games, surely, can't be enough to ensure that.
But a switch has been flicked and neither set of fans look game for kicking it back up. The M23 derby is fizzling out: the coast has extinguished the fire.