Book excerpt: Robert F. Kennedy was the first conspiracy theorist about his brother's murder. In this astonishingly compelling and convincing new account of the Kennedy years, acclaimed journalist David Talbot tells in a riveting, superbly researched narrative why, even on 22 November 1963, RFK had reason to believe that dark forces were at work in Dallas and reveals, for the first time, that he planned to open an investigation into the assassination had he become president in 1968. BROTHERS also portrays a JFK administration more besieged by internal enemies than has previously been realised, from within the Pentagon, the CIA, the FBI and the mafia. This frightening portrait of sinister elements within and without the government serves as the background for the emotionally charged journey of Robert Kennedy. Reading it, you can absolutely believe any number of people would have been happy for both brothers to meet a sticky end. The tragedy, not just for America but for the world, is that since their murders no one has had the nerve to stand against the dark forces they challenged in quite the same way.