Two Pulitzer Prize–winning journalists take an unbridled look into one of the most sensitive post-9/11 national security investigations, a breathtaking race to avert a second devastating terrorist attack on American soil.

In Enemies Within Matt Apuzzo and Adam Goldman lay bare the complex and often contradictory state of counterterrorism and intelligence in America through the pursuit of Najibullah Zazi, a terrorist bomber who trained under one of bin Laden's most trusted deputies. Zazi and his coconspirators represented America's greatest fear: a terrorist cell operating inside America. Apuzzo and Goldman lift the veil of secrecy to reveal the strengths and weaknesses of our counterterrorism measures. This real-life spy story—uncovered in previously unpublished secret NYPD documents and interviews with intelligence sources—shows that while many of these programs are more invasive than ever, they are often counterproductive at best.

Six months after the 9/11 attacks, New York police commissioner Ray Kelly initiated a straightforward yet audacious antiterrorist plan to be implemented in the Big Apple. The NYPD would dispatch a vast network of undercover officers and informants—known as 'mosque crawlers' and 'rakers'—into Muslim neighborhoods to eavesdrop on conversations in mosques and community centers. Police amassed data on innocent people, often for their religious and political beliefs. But when it mattered most, these strategies failed to identify the most imminent threats.

Enemies Within tackles the tough questions about the effectiveness of the measures we take to protect ourselves from real and perceived threats. Its shocking details about the tactics and activities of the NYPD will be headline news and reveal what it really takes to hunt down terrorists in America.