John Pearson knows more about the Krays than anyone alive. Legend, starring Tom Hardy, was based on his book The Profession of Violence and it was Pearson who exposed the Boothby connection in 1994. In 1967 the twins asked Pearson to write their biography. He remained a confidant of the family and the brothers throughout their trial and prison years. Now Pearson revisits the twins' criminal past and lays bare the truth behind the legend. Drawing upon a mass of first-hand interviews and private information he was unable to use while the Krays were still alive, he finally recounts the chilling untold story of the Kray twins.