Bayern 8, Barcelona 2. The End.

Lionel Messi turned his back. He had given the ball away, but he made no effort to atone for his error, no attempt to regain control. He stopped, waited a beat, and then looked to the other end of the field. It was as if he knew what was going to happen, and he did not care — or could not bear — to watch.

Once it had happened, Quique Sétien turned away, too, with a shake of the head and a shrug of the shoulders, looking to his coaching staff for an explanation or a bit of solace or confirmation that this was not real — because it could not be real — and it was all some horrible hallucination. On the field, his players stared, glassy-eyed. In the stands, his socially distanced substitutes kicked the seats in front of them in pain and rage and humiliation.

That was at seven. Bayern Munich had scored seven goals against mighty Barcelona, the Barcelona of Messi and Busquets and Piqué and Suárez, in a Champions League quarterfinal, with the whole world watching. It was unthinkable, unfathomable, unbearable. It was as low as they could fall.

And then Bayern Munich scored an eighth.

Rome was bad, in 2018. Barcelona had won the first leg of that quarterfinal easily, by 4-1 at Camp Nou. Few gave Roma much of a chance in the return: a chance to restore a bit of pride, maybe. But Barcelona collapsed, losing by 3-0. Messi and his teammates brooded on it for months. At the start of the next season, he gave a speech outlining his determination to put it right.

Anfield was worse, in 2019. Messi had been as good as his word. Barcelona had cruised to the semifinals this time, and had dismantled Liverpool on Catalan soil. Arturo Vidal, the grizzled Chilean midfielder, had promised to make a particularly personal donation to science if Barcelona did not make the final. Trent Alexander-Arnold took a corner quickly, and Barcelona buckled and broke.

But this? This was something else entirely. “The bottom,” was how Gerard Piqué, almost teary, put it. This was not a momentary lapse in concentration, a few minutes of madness. This was not hubris or overconfidence or some character flaw, unearthed in the white heat of the Stadio Olimpico or Anfield.

This was a brutal, ruthless, surgical exposure of all that is wrong with Barcelona. There is no need to reel through that long list — the dreadful recruitment, the total absence of planning, the boardroom infighting, the negligent squandering of a legacy — but, in the space of 90 minutes on Friday, Bayern Munich laid it all bare.

This was a box score to take the breath away, a result to end an era. That it was a player who has come to symbolize the wastefulness of the club, Philippe Coutinho — the most expensive player in Barcelona’s history, a player still owned by Barcelona — who delivered the coup de grâce has the tempting narrative feel of a parable, but the ultimate condemnation needs no explanation, no parenthesis. It was right there in the top left-hand corner of your screen. It was right there on the scoreboard. Eight. Barcelona conceded eight. That — and this is no exaggeration — can only be the end.

It will, certainly, be the end for Sétien. It was “too soon to say” if he will remain in place, he said after the game. What else could he say? He is a fundamentally decent, idealistic coach who is horribly out of his depth, but he is no fool. He knows full well how this plays out. He might have been fired on his way out of the Stadium of Light in Lisbon on Friday night. He might be fired at the airport on Saturday morning. He might be fired on the plane, or at the baggage carousel. But he will be fired.

Sétien will pay, one way or the other, because at Barcelona — as at all of the other misfiring super-clubs, the teams who now consider themselves too big to fail, who have forgotten that their size and their success is a direct corollary of the excellence they once embodied, not something bestowed on them in perpetuity by the divine — the coach always pays.

That is what happened to Ernesto Valverde, who made the fatal mistake of only winning two La Liga titles in two seasons and setting Barcelona on the path to a third. It is what would have happened, sooner or later, to Luis Enrique if he had not jumped, if not quite before he was pushed then because he knew the push always comes eventually. It is what happened to Tata Martino.

But that will not address the problem. Appointing Xavi Hernández — currently cutting his managerial teeth, in between promoting the wonderful, liberal existence on offer to everyone (please note: may not actually apply to everyone) in Qatar — or Mauricio Pochettino or whoever else the club’s redolent glamour can attract is not change of the order that Barcelona needs.

No, it is deeper than that, more far-reaching than that, more urgent than that. It was not just the score — again: eight, Bayern Munich scored eight — that stood out on Friday; it was Barcelona’s singular inability to do the things it is supposed to do.

Sétien did not tell Marc-Andre Ter Stegen, the most technical goalkeeper in soccer, to forget how to pass the ball. He did not come up with a scheme that involved his defenders and midfielders repeatedly playing themselves into trouble. He did not tell his players not to track their runners or to leave Bayern’s passing lanes open or to fail to drop back into defense.

Barcelona’s players remain, to a man, lavishly talented. Messi remains the finest player on the planet. But some have aged and others have not grown and some more have been brought into a team that does not suit their strengths.

This is not a team that can play as it wants to, as it is meant to. It is a team that has come to the end of its line, as even Piqué alluded to afterward, when he admitted that even he will have to leave, if that is what is best for the club. It is not a team that can compete with the finest clubs in Europe any more. It should have realized that at Anfield, really, but it cannot ignore it now. It is a team that needs to be broken up.

That is easier said than done, of course: Barcelona has the highest payroll in soccer hanging around its neck — its players earn more, on average, than any other team in any sport in the world — and the sorts of teams that might buy its expensive, aging stars are few and far between.

And besides, nobody would trust the current executive management of Barcelona to build again, to restore the team to its increasingly distant glory.

It is the leadership of Josep Maria Bartomeu, the president, that frittered away the prince’s ransom Paris St.-Germain paid for Neymar on Coutinho and Ousmane Dembélé. They are the ones who have spent three quarters of a billion euros on transfer fees since 2017 and managed to make the team worse, who have churned through sporting directors, who have watched on as prospect after prospect has left the club’s academy because the path to the first team was blocked.

Ultimately, that is where the blame should lie: with those who have overseen a decade in which the team that thrilled Europe under Pep Guardiola has withered away to a husk, who have wasted the final years of Messi’s peak, who brought Barcelona those nights in Rome, Liverpool and now Lisbon, with those who have brought Barcelona low, who have brought Barcelona here.

By the time the eighth went in, Barcelona’s players were barely moving. Sétien, too, was motionless. Under the glare of the floodlights, they looked haunted, shellshocked. The humiliation was a deeply public one, one that will follow them all for some time. Those that truly bear responsibility were spared that ordeal.

But there are some things that cannot be avoided. Eight. In a Champions League quarterfinal, against the mighty Barcelona, with the world watching on, Bayern Munich scored eight. For Sétien, certainly, for some of the players, most likely, and for this incarnation of Barcelona, this vision of it on the field and this regime off it, definitely, there is no return. This is the end.