David Headley, the American-Pakistani also known as Daood Gilani, lived a double life. One day he would stroll through Central Park in his tailored Armani suit as a true New Yorker, and the next he would browse in the bazaar in Lahore wearing traditional Pakistani clothes. One day he would drink champagne at the most extravagant clubs; on another he would prostrate himself in prayer in remote Pakistan and pledge fidelity to Allah.

Born in 1960, the son of an American mother and Pakistani father, with one blue eye and one brown, Headley grew up between East and West. He was attracted to both worlds, even working as an informant for the US government, until one day he found he had to choose between the place of his birth and a radical form of Islam preaching global jihad. This is the disturbing story of the mastermind behind the 2008 attacks in Mumbai that killed 166 people-who, two months later, flew to Copenhagen to plan another act of terror with the help of al-Qaeda sleeper cells in Europe.

Veteran journalist Kaare Sorensen has reconstructed his movements and planning in a tense feat of reportage. His account, based on extensive reporting, eyewitness interviews, and documentation, including wiretaps, court transcripts, and emails by Headley accessed from a chat room cache of 9000 messages, offers unprecedented insight into the mind of the terrorist.