With most novels, it's there, it's finished, now don't mess with it.

It was someone else's creation.

The idea, for example, that one author recently had the audacity to write a follow-up novel on what happened to Jane Austen's Emma and her Mr Knightley after they were sprinkled with confetti at the village church is horrifying.

Suzie Wong, however, is open for discussion; Richard Mason invited it before he died in 1997. American academic and author James Clapp fell in love with Nancy Kwan and Hong Kong on screen when he went to see The World of Suzie Wong, also at 19. Although he always enjoyed writing, he became a lecturer on urbanism, work that has brought him as a professor to Hong Kong several times in the past 10 years. But under the pseudonym Sebastian Gerard, he writes novels. For Goodness Sake, subtitled A Novel of the Afterlife of Suzie Wong and named with a nod to her pidgin English, may or may not be about Robert and Suzie back in Hong Kong. It is set in the first person, with protagonist American academic Marco Podesta coming to the territory. He, like California-based Clapp, is a professor of urbanism and arrives at a time of flux: the handover. Podesta lives in Sheung Wan, Clapp's favourite area in Hong Kong. While he studies the city and teaches students he falls in love with local Chinese girl Lily.

His obsession with finding Suzie starts when he catches sight of a painting in the window of a gallery in Sheung Wan: it is of a young Chinese woman in a ponytail and cheongsam who, he is convinced,

is Suzie Wong. One thing is clear: it is not for sale. The quest for the hidden tale behind the painting is the core around which the rest of the plot meanders, with a neat twist at the end.

There are three key Chinese women in the book: Lily, Podesta's on again/off again girlfriend; Grace, a younger friend whom Podesta sees as a sister; and Grace's aunt. There is also an artist and dealer called Robert Lomax, who owns the painting; he could be the Robert Lomax. He also could be deranged.

'I was on the Star Ferry [in 2000],' says Clapp, explaining how the novel originated. 'And I saw the back of a young woman with a long ponytail. Now, I know there are thousands of women in Hong Kong with ponytails, but somehow the film started rolling in my head and I started to write notes.'

Clapp's novel incorporates Wan Chai, the Star Ferry and his beloved Sheung Wan in a modern take on a story now more than half a century old. At one point Podesta stands looking out of his flat and musing on those living around him.

'Marco looks out at the buildings and has a list of imagined people and what they might be doing,' says Clapp. 'There's a couple glistening with perspiration making love, there's an elderly amah sleeping with her mouth open and a blaring television, a young boy engaging in self abuse as quietly as possible in a bathroom and an old man going to sleep for the last time.'

Clapp, 68, a grandfather, has struck up a friendship with Nancy Kwan, who wrote the preface to the novel. 'She's the same age as me ... three or four months older. But unlike me, she looks 20 years younger,' says Clapp, who became friends with Kwan through Australian film director Brian Jamieson, who's now making a documentary on Kwan due out this year. Clapp didn't have an audience in mind; it was just a book he wanted to write. But there is a cinematic aspect to his novel. 'I owe that to Denis,' he says, referring to his late friend and Academy Award-winning director Denis Sanders.

But it still reads like a novel.

If it is made into a movie, however, he would like to try writing the screenplay and have Kwan as Grace's aunt.

Mason wrote in a preface in a 1994 reprint of The World of Suzie Wong that Suzie would be long since divorced or dead, which is not necessarily what readers or film-goers want to hear about such a heroine. Here, Clapp has fun playing with the characters of Wong and Lomax, because they are fictional. But real people, albeit heavily disguised, also feature: Christine Loh Kung-wai has a cameo role but her identity is oblique enough 'to spare me any lawsuits', says Clapp.

Ever the urbanist, Clapp lets his love of the cityscape shine through. He even compares the city to a prostitute that has to please many customers. After his protagonist falls out with his girlfriend he stands in his melancholy by the Tsim Sha Tsui waterfront clock.

An image of the city accentuates his loneliness.

'It's a harsh axiom: you can love a city,' writes Clapp, 'but don't expect it to love you back.'

For Goodness Sake by Sebastian Gerard (Bamboo Books, HK$160)