Pilgrim was the codename for a world class and legendary secret agent. The adopted son of a wealthy New York family, he was once head of a secret internal affairs force for US intelligence and held the title ‘Rider of the Blue’. He wrote the definitive book on forensic investigation before disappearing into an anonymous retirement, taking the secrets of the Rider of the Blue with him. A murder in New York: the body of a woman is found facedown in a bath of acid, her features have been ripped from her face, her teeth are missing, her fingerprints gone. The rooms had been sprayed with DNA-eradicating spray. Someone has seemingly committed the perfect crime using the techniques outlined in Pilgrim’s book. A terrorist, known only as Saracen, was radicalised when, as a young boy, he witnessed the beheading of his father in a public square in Saudi Arabia. He has dedicated his life to destroying the special relationship between the Kingdom and the United States. He learnt his trade fighting the Soviets in Afghanistan, and now from hiding in Germany plots a terrible act of mass murder. When NYPD detective Ben Bradley tracks down Pilgrim, neither man can imagine the terrifying journey they are about to begin, as what begins as an unusual and challenging murder investigation leads them into a direct collision course with the dark forces of jihadist terrorism.