Celebrities and fringe theatre used not to be common bedfellows but many smaller companies are wising up to the promotional power of a famous name on the press release. In the case of Shatterbox Theatre Company’s Fair Trade, executive producer Emma Thompson has given more than just her name, pouring hours of creative development into the play, as well as a reported £20,000 of her own money in funds.

Originally performed at the Pleasance Islington in February 2009 and now playing in a revised version at Rich Mix before a month at the Edinburgh Fringe, Fair Trade tells the parallel true stories of two victims of sex trafficking, Elena (Anna Holbek) and Samai (Sarah Amankwah). Both dream of escape: Elena from her grey, poverty-stricken existence in a tiny Albanian village; Samai, from the horrors of bloodshed and civil war in Darfur. Both end up in London, where dreams soon dissolve into nightmares.

Shatterbox has avoided worthiness in this impressive production, punctuating unsentimental exposition of the facts with surreal sequences drawing on a range of dream myths from Cinderella to Hollywood. “There’s no such thing as fairy godmothers,” Buttons tells Cinders, but the play makes credible why thousands of girls just like Elena and Samai put their misguided trust in them every day.

Most disturbing is the scene where the girls lie on either side of the same bed as the male cast-members unbuckle their belts in never-ending succession around them. Broken, they proceed to tally up totals on the blackboard behind them, tallying, tallying until their chalk snaps with the effort.

A multi-talented cast switch fairly effortlessly between roles, in some cases playing both musical instruments and parts. It’s only a shame the scene transitions are not as smooth. Sordid subject matter like this cannot be tidied up but Shatterbox’s script still feels clunky at times and the stage over-cluttered.

And I can’t shake the feeling I’ve seen this play before. In a recent interview, Thompson said the problem of sex trafficking was not being talked about enough. In fact, physical theatre company The Paper Birds tackled the very same subject in their widely praised In A Thousand Pieces at Edinburgh 2008. The message bears repeating but we must be careful it doesn’t lose its impact.