Kwame Kwei-Armah's new play has a tempting subject: it chews over the difficulties facing a young, go-getting black man who's out to become mayor of London in 2012. What's more, the cast, directed by the playwright, adds considerable charm. If only Kwei-Armah didn't have such a short attention span here, picking up things that could be fruitfully developed, then dropping them. Jeremy Charles (Kobna Holdbrook-Smith) is an African-Caribbean television presenter whose celebrity skyrockets when he decks a knife-carrying black teenager, Lavelle. Before he knows it, he has been persuaded to run for public office. But can Jeremy retain his integrity, or will he simply become a figure manufactured to assuage white voters' anxieties? And will he be able to mentor the bright but wary Lavelle (Aml Ameen)? The play brushes past all sorts of issues, from the resentment raised by successful black men marrying white women, to Jeremy being told, "Brother, we just don't do Israel." Fortunately, Holdbrook-Smith's Jeremy, endearing and slappable in about equal measure, camouflages many of the script's weaknesses, even when he's spouting the kind of inspirational platitudes found on greeting cards.