There is a select group of fiction writers whose next book is eagerly anticipated by legions of fans around the world. Presenter Stephen Sackur speaks to a writer who has been in that club for two decades. Patricia Cornwell can lay claim to have invented the whole genre of crime scene, forensic detective fiction. Her investigator Kay Scarpetta has featured in two dozen novels, and inspired a host of imitators. The author herself talks of her determination to confront and control her fears - do her books tell us what she's frightened of?(Photo: Patricia Cornwell in the Hardtalk studio)