Among the many instructions issued to the people of Beijing for the next two and a half weeks are very specific guidelines on in-stadium behaviour and how to cheer their own athletes. But they have not been told how to respond when they see a Chinese player representing the United States. I refer to the American table tennis team, all four members of which are defectors.

Theirs, however, are not tales of undercover escape operations. Far from it. They are all proud to be back here. David Zhuang is 44 and says it was only the magnet of his former homeland that kept him in the game. Gao Jun won a silver medal for China in 1992 and would have been primed for gold in 1996, but fell in love and gave up the game to follow her heart to America. This is her last chance.

No, theirs is, collectively, an epic tale about pursuit of destiny, about crossing the world and back to find fulfilment. None more so than Wang Chen, who was born only three bus stops from Tiananmen Square and emigrated in 1998, but has been back staying with her parents in Beijing to prepare, with her father fretting that the “Olympic food” her mother has been serving is not up to scratch.

Remember, in China, table tennis is the national sport; they have tables in parks for the public to play on and businesses and factories often have a table tennis room rather than an employees' gym. Wang has been practising on the table in the machine factory where her father used to work and her father's friends have been calling to ask if she will give them a game.

Phelps wins first gold with world record

American swimmer sets world record in winning the 400m individual medley and the first of a projected eight gold medals

• Perfect stage for Michael Phelps, Mr Perfection

• Tom Daley heads into the deep

• Race against the clock

Multimedia

• Simon Barnes in Beijing

• Bring back the tug-of-war

• Top 100 Olympic athletes of all time

Wang's journey began aged 7, when the talent-spotters pitched up at her school asking the pupils if they could throw three tennis balls ten feet into a small basket. “It was not easy,” she recalled yesterday, “but we knew what it was about. I tried really hard.” Wang sank all three and was immediately put on a three-hours-a-night training regime. At the age of 11, she turned professional, was moved into an apartment with three peers and the hours per day went up to eight. Wang says she loved it, her competitive spirit rose and soon she was playing live every Saturday night on national television.

By the 1996 Olympics in Atlanta, aged 22, she was ranked fourth in a China squad that could select only three. So she missed out and, watching a battalion of youngsters moving up to usurp her, she quit two years later.

This is the point about the Chinese: strength in depth. So much so that defecting table tennis players are commonplace; about a third of the rest of the world's competitors here in the Olympic tournament are Chinese-born or Chinese-trained. Indeed, it has got to the stage where the international federation recently brought in strict rules that effectively rule out nation swapping, meaning that Wang and her like will not be seen again.

Wang is here only because of the investment of another of life's travellers. In 2000, she moved to New York to help her sister, who ran two leather goods stores, but also started giving table tennis lessons. One of her students, Jerry Wartski, is a Polish Jew who survived Nazi concentration camps and three years at a displaced person's camp outside Frankfurt. He now owns properties in New York, among them table tennis clubs, and was soon bankrolling Wang's comeback all the way into the US team.

She feels as though she is American and Chinese, and hopes to be allowed to march in today's opening ceremony with the Stars and Stripes painted on one side of her face and the star of China on the other. Wang is confident the Chinese crowd will respond well to her. The Chinese, she explained, are more interested in close competition, and anyway: “I have a lot of friends in Beijing; they will all cheer for me.”

As for Gao, her marriage failed and she has been back in China for eight years, training to play for the US. She is undecided whether she will return to America after the Olympics. For Wang, there is the commitment to play the games she has promised her father's friends, then she will return, again leaving half of her life behind.