If the jury has not yet decided whether Kevin Pietersen burned too quickly, too fiercely, and made too many assumptions about the depth of his own brilliant talent, it had better be paying attention here today.
He has passed this way before, of course, facing down the taunt that he is a traitor to his native land and an ingrate, and prospering with that boldness which made him such a force of light and confidence in the great Ashes series of 2005.
But it will be different today when the guttural jeers of the most stubborn Boers again assault his ears. It will be different because Pietersen, we have to believe, is different. Is he weaker, more vulnerable than ever before? Maybe he is, maybe he is not, but that he is changed, in his mood, and the extent of his concerns, there is no doubt.
When he came here five years ago as a new England player he was certainly reviled but it was, as he recalls, "water off a duck's back. I loved the edge it gave, I loved the pressure." He said something of the same when he joined his captain Michael Vaughan at the wicket and the crowd at the Wanderers ground in Johannesburg was baying so hard it might have time-travelled from the Roman Colosseum. Vaughan was stunned by the casual, brassy authority of the young man in the eye of the tumult.
Pietersen wore a bizarre white streak in his hair then but down his back there was not a hint of any shade of yellow or doubt, nor even an occasional hint of reflection.
That is what so enraged the South Africans. It was enough that he should come home in enemy colours, worse that he made it seem like just another jaunt.
It will be no kind of easy passage today, unless he can defy the circumstances and do so with some of the force that has been elusive for so long. Indeed, the odds insist it will be one of the fiercest examinations a leading sportsman has ever received.
South Africa captain Graeme Smith, like the rest of the nation perhaps sensing that the great talent who left home complaining about the iniquities of positive discrimination in the selection of national teams now has some demons of his own to banish, racked up the pressure yesterday.
South Africa, said Smith, would fight England man for man but there was no point in hiding the fact that something special was being reserved for Pietersen, whose fight to recover from the serious Achilles tendon injury that drove him out of the Ashes series last summer has so far been rather more dogged than coruscating.
Smith said: "I would like to make it a major test for him. That is our challenge as a team and we would like to put all the English batsmen under pressure. We've worked on a few interesting game plans for him, though, and hopefully we will put them into place tomorrow."
"Interesting game plans" sounds like a phrase you might hear on the lips of some arch cricket theorist but in this case we can strip it down to its essentials. It is not about tactical nuances. It concerns the raw strategy of hitting hardest at a point of suspected weakness, turning self-doubt into an authentic ordeal. The sledging, we can be sure, will come in an avalanche.
The gameplan is to assault the confidence of a man who in the past few years has surely been separated from at least some of the certainties that came when he walked to the wicket not as just another gifted batsman seeking superior results – and to confirm his place as the most desirable, and expensive, cricketer in the world – but someone who could make the improbable and the devastating commonplace.
Two years ago Pietersen married his pop star girlfriend Jessica Taylor and announced that he was entering a new phase of his life. He just wanted to play cricket and raise a family. He was putting behind him the "old malarkey" of bling and partying, of the life of an upwardly mobile celebrity. He was tempered too by the terrorist outrage in Mumbai, returning to the scene of carnage at the hotel where England had only recently stayed – and then cast down by his controversial loss of the captaincy.
These were sobering developments even before the most destabilising of blows in the life of a professional sportsman, the first serious insight into how a major injury can sweep away everything you had believed was secure in your future.
Such is the background to Pietersen's imminent walk into the teeth of the sharply surfacing doubts about his continued omnipotence and the renewed hostility of a Centurion crowd that have seen their team triumph 11 times in 14 Tests.
If Pietersen needs encouragement, he might have found some in the words of his captain Andrew Strauss, who discovered a little bit about pressure when he was asked to rebuild England amid the chaos that came with Pietersen's "resignation" at the start of the year.
First, though, Strauss scarcely dismissed the suggestion that his predecessor may never have played in a Test match so pivotal to his sense of well-being. Strauss said: "I think KP found himself in quite an unfamiliar position at the start of this tour. He had been playing cricket almost continuously for God-knows-how-long and it's the first time in his England career he has had time away and had to find his feet again. So that has taken some adjusting to and you have to build your way up through the gears.
"I'm very happy with the way he has been going about things. He has been training exceptionally hard. I think he has been looking better and better and KP being the kind of person he is he will want to have a massive impact on this series. When you combine that motivation with his skills I think it's a pretty good recipe."
Wrecking the dish is, though, plainly a South African priority. Smith speaks candidly about the concerted effort to subvert the will of Pietersen, saying: "Since his injury he has been scratching for a bit of confidence and we want to keep him under pressure, as we have done throughout the one-day series and tour so far.
"With regards to the off-field stuff, that's out of our control and we are going to focus on playing England man-for-man. Kevin is carrying a burden here for comments he has made over a period of time. So we've just got to live with those and get on – and hopefully cricket will be the winner."
Such a pretty sentiment is unlikely to survive a wave of hostility that will only be beaten down by some timely resurrection of the old Pietersen mastery. It will, anyway, be the most visible drama of a series that has the potential to remind us that one good Test, keenly fought and with a little of the salt of lurking enmity in the air, is worth at least a thousand of the more abbreviated versions of the game.
South Africa want to restate their potential to be the No 1 Test nation. England will seek to confirm the significance of an extraordinary Ashes win. Meanwhile, Kevin Pietersen has hugely testing ambition of his own, one that could easily prove the most decisive single factor of all over the next five days. He wants to remind everyone that he still has the means to be the world's greatest batsman.
It is, at the very least, something compelling to put before perhaps the most rancorous jury cricket is ever likely to hear.