Stephen Sackur speaks to author Margaret Atwood. There are writers of world renown whose reputation rests on one great book. There are others who write more prolifically but always in the same territory. Margaret Atwood's output fizzes with energy, diversity and experimentation. She's best known for her novels The Handmaid's Tale, The Blind Assassin and Oryx and Crake. But she's written poetry, blog fiction and in 2016 a superhero comic book. She has a worldwide legion of fans - what keeps her creative juices flowing?