One of the most incendiary rivalries in world football will be renewed on Sunday when Glasgow foes Celtic and Rangers meet for the first time in almost three years in a Scottish League Cup semifinal.
Their 400th match will be an "Old Firm" showdown like no other, however.
Celtic and Rangers are usually neck-and-neck atop the Scottish league standings -- they have a combined 99 league titles -- but the chasm between them has rarely been wider.
While Celtic is on course for a fourth straight Scottish Premiership title, Rangers is in the second tier and scrambling its way back up the league pyramid after being demoted to the bottom division in 2012 for financial mismanagement. Rangers remains in disarray, with the club's financial position perilous, and team manager Ally McCoist having recently quit.
It has led former Celtic striker Chris Sutton to say this week that his old team could win virtually blindfolded, comments which will stoke up the tension for a match that never lacks an edge, and always puts Scotland's police and football authorities on high alert.
"There is no comparison with an Old Firm game," former Rangers midfielder Ronald de Boer told the Daily Mail. This comes from a player who has appeared in a World Cup semifinal for the Netherlands and clasico matches for Barcelona against Real Madrid.
A volatile mix of religion, politics, and fierce sporting rivalry means Celtic-Rangers matches run deeper than just a simple game of football. Rangers has a traditionally Protestant fan base, and Celtic's supporters are more likely to be Roman Catholics, meaning fan clashes and violence are commonplace in and outside stadiums.
In a notorious Old Firm game in 2011, three players were sent off, there were 12 yellow cards, the two managers squared up to each other at the final whistle, and 187 fans were detained by police on the day of the match. The then-Scottish First Minister, Alex Salmond, held a summit with representatives of the clubs in the following days amid calls for the fixture to be scrapped.
Three years on from their last meeting, though, there is a fresh appetite for a game that puts Scottish football on the map -- even if it's for the wrong reasons.
"Everyone all over the world will be watching, and hopefully we can put on a show for them," Celtic captain Scott Brown said. "Do we miss Rangers? Yes, on occasions like this."
With players such as De Boer and Danish star Michael Laudrup, Rangers was once a regular in the Champions League and was a beaten finalist in the UEFA Cup -- the precursor to the Europa League -- in 2008. Now its team is full of players unknown to global audiences and is a massive underdog this weekend.
The buildup to the game has been typically fraught, with a group of Celtic fans paying 3,000 pounds ($4,500) to have an advert in one of Scotland's top papers saying this actually will be the first ever match between the two teams. That makes reference to the fact that the "old" Rangers went out of business in 2012, and the current team is the "newco" Rangers.
Indeed, when the famous blue shirts run out on Sunday at Hampden Park, it will mark the start in a new Old Firm era. But the age-old rivalry will not have disappeared.