South Africa Letter: The woman occupying the seat on my right - and just a little of my own seat as well - exuded confidence and security. She was smartly but sexily dressed for business, and was sending a string of e-mails on a state-of-the-art PDA as we waited for take-off in Johannesburg.
The boy - alright, young man - on my left looked nervous and displaced, constantly fidgeting with his Ipod, eyes zapping around the cabin as if he had had too little sleep, or perhaps too much of something else.
I'd noticed they had been engaged in intense conversation when I moved between them. It soon resumed. She was questioning him, with almost missionary zeal, but also patently sincere concern, about what he intended to do with his life. And, more importantly for her, about where he intended to do it.
"I'm crewing a small boat back to England," he told her, "and then I'm going to join the Royal Marines." "But why don't you stay here and join the South African navy?" she asked him.
"Because I was born in England," he said, and for some reason it seemed as if even he felt he was fobbing off her real question. So he suddenly added, as if it really explained everything: "Besides, 90 per cent of the South African navy can't swim." This had to be a euphemism, but it was a new on me. White men can't jump - I know that one - so perhaps black sailors can't swim.
However, before I could pursue this line of thought, she was ploughing ahead into the territory she wanted to reach, gentle but unrelenting.
"I know what you are really thinking," she told him. "You think you will not get a job because of black empowerment, because of quotas. Or you won't get the job you should get, the job you deserve."
"Maybe," he said, a little embarrassed.
"Well," she said, "it is hard on you young white people now, believe me, I understand that. But black empowerment is necessary in the short term. We have a lot of ground to make up. It won't last forever, just until things are more even.
"But please, please, think of this as your country too. We need people like you to stay here."
"I want to stay," he said, "or at least I want to come back, and start a business here, after the navy." And then he challenged her, suddenly a little angry.
"The problem here for us is not just jobs," he said, "it's racism. Some black people hate us. I've been robbed and knifed twice on the street. I've been car-jacked twice, at gunpoint."
She did not try any of the counter-arguments. She did not say that he had been robbed not because he was white, but because he had something and the people who robbed him had nothing. Nor that the gangs who organise car-jacking are controlled by white crime bosses, as seems to be the case.
"That is bad," she said. "That is very, very bad. I am sorry." But after a moment's silence she was as irrepressibly optimistic as ever. "But it will get better. It will. If people like you stay here, if we all work together." The young man seemed mollified. It was certainly an encounter he was unlikely to forget.
I recounted this story to an Afrikaans-speaking white friend a few days later. "What is remarkable about this country," he said, "is not the crime and the hatred, but the tolerance and generosity, after all that has happened. People of all races are making a huge effort, every day, to get on with one another."
That might sound bland, but he said it just after he had pointed out one of the new South Africa's grimmer monuments.
This is a green hill, deep in the northern province of Limpopo, studded with white crosses. There are hundreds of them, and each commemorates a white farmer murdered since 1993.
At least they can be counted and commemorated. No one knows exactly how many black people are murdered and raped in the townships, where crime claims most of its victims.
A few nights earlier, I had found myself in such a township, after a wrong turn on an unlit road. I took a blind corner wide, and instinctively slowed to apologise to an oncoming driver.
"I think you are lost," the driver said slowly and reassuringly. "Why don't you just turn and follow me. I will take you out of here." One more time, the kindness of a stranger rekindled the hope that the new South Africa might really be, one day, a rainbow nation.