Open Book - 26/04/2009

British author Hilary Mantel explains why Thomas Cromwell, the hero in her new historic novel Wolf Hall - far from being Henry VIII's Machiavellian advisor - just had an image problem. Zimbabwean writer Brian Chikwava's debut novel Harare North inspires a discussion about recurrent themes visited by expatriated African writers. Will Self's Reader's Guide to the late JG Ballard is revisited. And Professor John Sutherland takes a look at fictional dentists in this week's Reading Clinic.