It's a nonfiction book prize that values "style, rigour, argument, meatiness, readability, freshness, oddity and individuality," says Minoo Dinshaw, author of Friends in Youth and one of this year's judges. He introduces the six brilliant books that made the shortlist of this year's Pol Roger Duff Cooper Prize, from the history of post-World War II Italy to the disputes caused by the discovery of dinosaur fossils.