Mariella Frostrup talks to the Australian novelist Christos Tsiolkas, whose debut The Slap won the 2009 Commonwealth Writers Prize. The book tells the story of a father who rashly smacks a child who is not his own at a family barbecue - and the drastic consequences of that event. The author talks about the incident that prompted the novel, and reflects on his experience of multicultural Australia. A new series of novels about the teenage years of Sherlock Holmes, authorised by the author's literary estate, is launched this month. Mariella is joined by the media lawyer Duncan Lamont and the critic Peter Kemp to discuss the rights and wrongs of writing a book using another author's hero. And D J Taylor offer's a Reader's Guide to the work of J B Priestley, a hugely successful and prolific writer who was once removed from the BBC airwaves for being too popular. Producer: Thomas Morris.