In the Writer's Retreat, Chika Unigwe is describing the initial culture shock of moving from Nigeria to Brussels, which included mistakes of ettiquette and, for the first time, seeing sex workers displayed in windows. Coming from a country where prostitution is underground, this image stayed with the author and eventually influenced On Black Sisters' Street.

Unigwe is concerned with a particular sort of feminism: subversion of power through subtle means. She illustrates this by describing a short story she wrote about a woman who had her tubes tied to take revenge on her verbally-abusive husband, who felt he was a failure for not producing sons.

The author's research for the novel involved dressing in a short skirt and thigh-high boots and visiting an Antwerp cafe frequented by Nigerian prostitutes. Her conversations with the women there inspired the characters of the sex workers and several others in the novel. Unigwe also consulted a Nigerian woman in Italy who runs a halfway house for women who wish to leave prostitution.

Unigwe's representation of prostitution as some women's route to empowerment might raise a few eyebrows amongst traditional feminists - but it is relevant to current discourse in addressing the experience of women who live outside the white, middle class group - those who have traditionally dictated the acceptable routes to empowerment. The same can be said of the author's depiction of Nigerian women whose debts to pimps or brothel owners are bought by their Belgian husbands, or the notion of a pimp as a safer alternative to arriving alone and being auctioned.

On the subject of black sisterhood, Unigwe refers to her relationships with her actual sisters, and with her community. She currently lives in a small, isolated community in Belgium, where she is a town counselor, but she had to pull her son out of summer camp when the activities coordinators refused to alter games designed to reinforce African stereotypes. Raffia skirts and war paint, apparently...incredibly.

The depictions of official corruption in the novel has ruffled a few feathers. Unigwe asserts that this is based on real accounts from the women she spoke with; stories of being smuggled through Heathrow by a customs officer bribed by a pimp in Nigeria, or of Belgian immigration police offering to destroy arrest records for cash bribes or sex.

There's a spatter of rain as I make my way along the boardwalk, and Charlotte Square is filling with the after-work crowd. The more impatient amongst us walk through the muddy grass to get around the slow-moving traffic on the boardwalks.