It is the court hearing that could reshape European football and determine whether the Super League, as still desired by a quarter of the dozen clubs to have publicly backed the proposal last April, remains a live prospect.
This week at the European Court of Justice in Luxembourg case C-333/21 will be heard.
The case revolves around the European Superleague Company - nominally Barcelona, Real Madrid and Juventus - claiming that the game's governing bodies - UEFA and FIFA - have monopolised the organisation of elite football competitions and acted beyond their constitution by shutting down the plans for a new breakaway league.
The clubs' argument that the governing bodies violated competition law have already been heard in a Madrid court, which referred the case to the ECJ, and this two-day hearing will be focused on intricacies of the European Union 's regulations.
"[UEFA] acted as a cartel and misused its dominant position on the market for the organisation of international football club competitions in Europe and on the market for the commercialisation of the rights attached to these competitions," the European Superleague Company claims in its filing.
More than a dozen European governments have backed UEFA, the domestic leagues are behind them and, in England at least, the feeling of supporters towards a closed shop competition requires little elaboration.
And yet a ruling in favour of the three clubs could provide the concept with a gusty second wind.
"Of course it is still alive," Real Madrid president Florentino Perez said on El Chiringuito last month. "We believe that we have the right, within the European community, to organise competitions between us, with UEFA. We understand that UEFA is a monopoly and in this Europe of 27 [EU member states] a pillar is that of competition."
In a statement posted on UEFA's Twitter account after the ECJ confirmed at the end of May that the case would be heard in mid-July, the governing body said it "is confident in its position and will defend it robustly."
Separately UEFA has vowed to punish the three clubs, including a potential ban from the Champions League and fines, with that likely dependent on what the ECJ decides.
Aleksander Ceferin, the UEFA president, has accused the clubs of living in a "parallel world" and the head of La Liga Javier Tebas claimed in March that senior figures at all three are worse liars than Vladimir Putin. The clubs, meanwhile, argue that "either we reform football or we will have to watch its inevitable downfall" under the current structure.
Perez has played down the threat of a Champions League ban - "we have never had that fear, and that was when they said it at the beginning" - but for Real to be suspended from the competition that matters most would almost certainly reverse their present stance.
That is all to come in a saga no closer to its final chapter.
There will not be a verdict for months but a ruling could also have an impact beyond football; setting a precedent that may result in similar claims being made in other sports.
"It needs to be appreciated that the case is wider in scope than just focussing on the ability of the governing bodies to impose sanctions on the clubs that were earmarked for participation had they pursued their involvement further," explained Stephen Taylor Heath, head of sports law at JMW Solicitors.
"The easiest argument for UEFA to succeed with is that they retain the right to determine the rules under which a club can participate in the event properties they control even if it means being unable to participate in a rival competition.
"UEFA cannot however have a constitution or a rule book that breaches applicable law. An obvious, extreme example would be rules as to participation that were deemed to be discriminatory.
"Rather it goes to some fundamental issues regarding governance of football that could have repercussions in other sports as well particularly where that governance amounts to a monopoly."
It would not be the first time that an ECJ decision potentially altered football beyond recognition. In 1995 they ruled on the case of Jean-Marc Bosman, allowing players to move freely at the end of their contracts, and turned the transfer market upside down.
Siding with the Super League three may have even more seismic long-term implications.