This is the story of the most dangerous triple-agent in US history. Peter Lance, author of the highly acclaimed 1000 Years for Revenge and Cover Up, returns to uncover the story of Ali Mohamed, a trusted security advisor of Osama bin Laden who hoodwinked the United States for more than a decade.

As Lance reveals for this first time, this one man served in a series of high-security position within the United States security establishment, as a Special Forces advisor, FBI informant, and CIA operative, while simultaneously helping orchestrate the al Qaeda campaign of terror that led to 9/11. In October 2000, after tricking three US intelligence agencies for almost two decades, Ali Mohamed appeared in handcuffs and a blue prison jumpsuit in a Federal District courtroom on Manhattan's Lower East Side, where he pleaded guilty five times. His crimes included brokering terror summits, financing an attack on two Black Hawk helicopters, training jihadis in improvised bomb building, and the creation of secret cells. And yet, for decades Mohamed had lived the life of a Silicon Valley computer executive. How this evildoer moved in and out of and around the US is just one of the questions answered. From the Able Danger scandal of the Clinton Administration to today's CIA Leakgate, Mohamed appears at nearly every crucial turn of America's terror probes.

An important final piece to the 9/11 investigation, Triple Cross penetrates Mohamed's secret past and the dark reaches of Al Qaeda to reveal the danger that still threatens America and its internal security.