All the talk has been of cycles of strength and weakness, how one has put England up and another left Australia down. Some things, though, are eternal. They include, if we ever doubted it, the sublime shot-making ability of Kevin Pietersen.
On Sunday, every English hope and Aussie fear was fulfilled with a great mountain of evidence that at the age of 30, and with the experience of 66 Tests, he has come here with both a new head and an old, natural-born brilliance.
He certainly made each second of the time Ricky Ponting and his demoralised Australian team spent on the field an excruciating ordeal of powerlessness and humiliation.
When he stepped down the wicket to dispatch Xavier Doherty, who represents the latest desperate attempt to find just a glimmer of a slow-bowling threat in the void left by Shane Warne, to hit him for a vast straight six, it seemed like the right time for intervention from the League Against Cruel Sports.
Instead, there was thunder and rain and a hold-up in the slaughter. It was not nearly enough, however, to wash away the reality that this second Test had thrown up one crushing fact.
It is that only a miracle of suspended logic can stop England retaining the Ashes in the next few weeks.
The weather forecast said that there would be showers and maybe a storm or two. But the cricket forecast could be made much more confidently. This said that with the accumulation of poise and authority and, most vitally, sound judgment displayed by Pietersen in his 17th Test century and second double hundred, the last serious question mark against England's prospects had been removed.
Some of his warmer admirers will, of course, dispute the existence of the question in the first place. But they will be wrong because if we knew of his ability to make the most beautiful runs we were increasingly aware of the strange and apparently growing vulnerability of his nature.
The fall-out from his failed captaincy of England was heavy and disturbing. His behaviour became ever more skittish, immature. It was though the world had seriously underplayed its understanding of how great a performer he was, and no matter that his technique and decision-making was shredding before our eyes.
When he was dropped, after a golden duck of mind-blowing irresponsibility against the Pakistanis, and advised to spend some time on re-establishing the fundamentals of his batting, he tweeted his anger, even disbelief.
He railed more passionately than any of his team-mates against the decision to put the presence of the Wags on hold until the team move to Perth for the third Test next week. The Aussies, naturally, rubbed their hands. Here on Sunday though they stopped doing that. They started wringing them, as well they might have done.
No longer was Pietersen, a hero in England in 2005 when the Ashes were regained and one of the few points of significant resistance in the subsequent whitewash here in 2006-07, a sledger's dream, a virtuoso talent but a walking accident zone when the action became most intense. For four hours here on Sunday, Pietersen was nothing less than a batting god.
He was straight and remorselessly precise in almost everything he did. He received 296 deliveries and, apart from the volcanic six, hit 31 of them to the boundary ropes. One of them was so cruel it might have been conceived by the Spanish Inquisition. It dissected, quite surgically, Mike Hussey and Doug Bollinger who had been placed on the boundary to police attempted hooks.
When they failed to stop the rippling ground shot, a huge collective groan rose up from the terracing. They looked at each other as shell shock victims might.
Ponting appears increasingly like a man pushed to the brink by Pietersen's extraordinary assault. He could not know the scale of the criticism building around him beyond the field, but no doubt he could guess. His old ally Warne has been taking free shots for some time and yesterday former captain Ian Chappell, the local champion for whom, with his brother Greg, one of the stands in this exquisite ground is named, joined the mob.
Appalled by Ponting's defence measures in the field, Chappell declared: "If a bowler is asked to bowl with a 7-2 field he's entitled to throw the ball back to the captain and say, 'you bowl it yourself'."
The meaning of Ponting's career is still too great here to permit such an insurrection but there is no doubt the growing likelihood that he is staring at a third Ashes defeat is making heavy inroads into his old swaggering self-belief.
This grim possibility had already been brought into sharp focus by the impressive form of Alastair Cook, Jonathan Trott and Jimmy Anderson here and in Brisbane, where captain Andrew Strauss sandwiched a century that would go between two cheap dismissals, but Pietersen's performance came on an entirely different dimension.
It was, quite simply, a masterpiece of batsmanship. There was the superb, hypnotic belief that here was a professional sportsman who had, before it was too late, concluded that here was an opportunity that might never come again.
So the day had to be not so much taken as consumed. It had to be used for an expression of some of the most enviable natural ability ever handed down to a cricketer. It had to provide the hard evidence that he had seen where he had been going wrong and, here it was, the gorgeously produced proof that he had found a solution.
Later he spoke in hushed and humble tones, stressing that his only priority was the team. That may or may not be a new truth in the life of Kevin Pietersen but for one day, at least, English cricket had no reason to care either way. With Australia on their knees, it was surely enough that he had done something other, and maybe more, than become merely a model team-mate. It was to look, for a little while at least, quite the best batsman in the world.
Chief Sports Writer at Adelaide Oval