On the ground floor of the Guggenheim Museum, a mile or so from the stadium where the Europa League final takes place on Wednesday night, they are showing a contemporary film and video exhibition, a collaboration between Basque and Italian artists.
Crowds of visitors enter the exhibition room in darkness, strangers bump into each other while they wait for the video to start, people walk into walls as they grope through the gloom and start to wonder how they will ever get out.
When the films begin, they have a nightmarish quality. A man in sunglasses, his image blurred and grainy, feints to his right again and again. On another screen, a man groans and then hums a dissonant tune that grows quick and angry. Finally, a man's voice. 'You're not ready to see this yet,' it says.
Someone at the Guggenheim knew Manchester United and Tottenham Hotspur were coming to town, clearly. They knew that Ruben Amorim and Ange Postecoglou, managers tortured by the mediocrity of their teams, would be bringing their suffering with them, too.
Maybe they knew that by Tuesday evening Postecoglou would be in a press conference, raging at the suggestion he would be dismissed as a clown if Spurs lose. Maybe they knew that Amorim, who has a predilection for self-flagellation, would be answering more questions about the staff redundancies and petty cutbacks at Old Trafford that have contributed to the grim narrative of United's season.
On one level, what is approaching here in this beautiful city in the Basque Country is a final with absurdly high stakes that promises either redemption or ruin for English football's lost souls. And on another, it is a collision of the damned.
United and Spurs have been so poor this season - they lie 16th and 17th in the Premier League - that it is difficult to know whether to be proud two English teams have reached a major European final, or to be embarrassed.
Statistically, in terms of their collective current positions in one of Europe's top five leagues, they are the worst two teams ever to appear in a European final. With a nod to the host nation, some are calling this clash El Crapico, although it would have taken a brave journalist to mention that to Postecoglou. Nobody did.
So is this heaven or is this hell? What does it say about the imbalance in European football that has been created by the financial might of the English top flight that two sides as thoroughly and deeply mediocre as United and Spurs can get to this final?
The Spurs and United fans who have made all manner of wonderful odysseys to get here, ferries from Plymouth to Santander or Portsmouth to Bilbao, planes to Biarritz or Bordeaux or Toulouse or Madrid or Barcelona or Porto, and trains and hire cars through the Pyrenees to complete the journeys will care little about that question.
What both sets of supporters do know is that by the end of the game in this magnificent stadium on the banks of the Nervion River, one of their teams will be looking forward to playing in the Champions League next season and the other will be drowning in ridicule and despair.
So they are enjoying it while they can. When the Spurs team bus arrived in Bilbao Tuesday lunchtime, it was followed around the Plaza del Sagrado Corazon de Jesus by chanting fans. Those chants even infiltrated the Guggenheim.
United fans were here in force on Monday evening, too, singing and carousing in the older section of the city that rises up from the banks of the river towards the steep hillsides that gaze down on Bilbao. They have tasted glory more recently than Spurs but their team's fall from grace has been even more startling.
The pressure is intense for both managers. So much is riding on the final that it is hard to know if either will survive defeat by the other. Part of the equation is money. The carrot of Champions League qualification means victory is worth more than £100million to the winner.
Victory means a higher calibre of signings in the summer. Victory means a chance to end the agony. Victory means the glimpse of an upward trajectory.
Defeat does not bear thinking about. It means a season without European competition. It means vastly reduced revenue. It means penalty payments to disappointed sponsors. It means losing more and more ground to the Premier League's top sides and moving further and further away from the European elite.
For Spurs, in particular, victory means a chance to change the mocking narrative that yaps at them. You know the stuff I mean: the joke about 'Doctor Tottenham will see you now' that aims at the club's ability to cure the ills of others by losing to them, the invention of the adjective 'Spursy' that describes the ability to snatch defeat from the jaws of victory.
They have not won a trophy since they lifted the League Cup in 2008. They have not won a European trophy since they beat Anderlecht to win the UEFA Cup in 1984. 'This game represents the chance to change the history of our club and the mentality,' the Spurs captain Son Heung-min said when Tottenham began their training session at the San Mames.
All that is on the line on Wednesday evening, so maybe it was not a surprise that Postecoglou reacted so angrily when he turned up for his press conference yesterday and was asked about flirting with infamy by a reporter, who had speculated recently in his newspaper that some might brand him a clown if Spurs lost.
'That depends on your outlook,' Postecoglou spat back, 'but I'll tell you one thing, irrespective of tomorrow, I'm not a clown and never will be. You really disappointed me that you used such terminology to describe a person that for 26 years, without any favours from anyone, has worked his way to a position where he is leading out a club in a European final.
'For you to suggest that somehow us not being successful means that I'm a clown, I'm not sure how to answer that question.'
When Amorim took his seat at the same dais a couple of hours later, he cut an altogether more relaxed figure as he sat between Bruno Fernandes and Harry Maguire. Fernandes even felt able to make a joke at Amorim's expense when the manager was asked why it was that he was not under as much pressure as Postecoglou. 'He is,' Fernandes said with a mischievous smile. Amorim laughed. 'He wants my job,' the United boss said.
Amorim has sought to play down the wider importance of the result. The club have said, for instance, that they will not have an open-top bus parade if they win tonight. A barbecue has been suggested instead.
'There are a lot of problems we need to solve in this club and they will not be solved by winning a cup,' Amorim said.
Spurs have the advantage of having beaten United three times already this season, home and away in the Premier League and also in the Carabao Cup. But they also have to cope with the issue that three of their best players - James Maddison, Lucas Bergvall and Dejan Kulusevski - are out through injury.
Maybe their absences accounted for Postecoglou's dark mood. His biting sarcasm was never far from the surface and it re-emerged when he was asked a question about his future.
'I will keep on winning trophies until I finish, wherever that is,' he said. 'Don't worry about my future, mate. Don't stress, mate. Sleep easy.'
The truth is few will rest easy ahead of this game. It is too big. It is all or nothing. As Amorim and Postecoglou and their players headed back to their hotels, the blurred images of haunted men still twitched and flitted across the screens at the Guggenheim. And those voices still hummed angrily in the darkness.