Rana Mitter talks to the art critic Andrew Graham Dixon about his new biography of Caravaggio, and what police records of the time tell us about the violent world in which Caravaggio lived - including his life on the run after he killed a criminal, Ranuccio Tomassoni, in a duel in Rome. Rana hosts a discussion of how markets can promote or hinder environmental issues, with the author Heather Rogers challenging many of the sacred cows of environmentalism, and the economist Catherine Cameron arguing that green issues would be best left to the market. Jay Kennedy of Manchester University believes he has discovered a hidden musical and mathematical code in Plato's works, which unlocks previously unknown areas of Platonic thought. To find out if this news will change how we read Plato, Rana is joined by Jay Kennedy and Professor of Ancient Philosophy, Mary Margaret McCabe. And two Chinese directors, Jing Guo and Dingding Ke, join Rana to talk about life in modern Shanghai, and their television portraits of this city. A competitive spirit permeates each programme - from the pressure to achieve high grades at a progressive primary school; for children in hours of acrobatic practice in the city's famous circus school; and in adult life - with one Shanghai businessman working every waking hour, every day of the week.