From the New York Times bestselling author of The Only Plane in the Sky: An Oral History of 9/11, a speculative nonfiction thriller about the little-known terrorist plot that upended the United States government just weeks after the September 11 attacks.

Barely a month after four planes were hijacked and directed at U.S. targets on September 11, 2001, a CIA source from Afghanistan—code name: Dragonfire—reported an even more terrifying development: terrorists linked to al-Qaeda had smuggled a nuclear device into New York City. As the U.S. government struggled to mount a response to the horrifying 9/11 attacks, this new threat came as a stunning blow. It was the worst of worst-case scenarios. Was an American Hiroshima about to occur? 

As the fires at the World Trade Center still burned, a small, top-secret cadre of FBI agents, CIA officers, and counterterrorism experts worked around the clock, trying to track down a nuclear bomb that could be anywhere from the Bronx to Lower Manhattan and could detonate at any moment, killing thousands and wreaking havoc on the U.S. economy. No one else in the country, not even New York officials, was alerted to this threat, for fear of the widespread panic that would ensue.

It would be months before news of the incident came out, but the details were so scant, few took notice. And the mystery remained: Was Dragonfire correct about the bomb? There was obviously no explosion in New York City, but was it because the bomb didn’t exist, or because it was found and disabled in time?

For years, Garrett Graff tried to get the whole story. As the acclaimed author of numerous books about counterterrorism and national security, including The Threat Matrix, Raven Rock, and the New York Times bestseller The Only Plane in the Sky: An Oral History of 9/11, Graff had the trust of officials at all levels of the FBI, CIA, and the executive branch, who knew him as a smart and responsible journalist. But when it came to uncovering the truth about the Dragonfire incident, he was repeatedly stonewalled. There was clearly much more to the story than had been reported. But what? Why were people so skittish talking about a threat that had supposedly been easily dealt with years earlier? What if the plot wasn’t actually as harmless as we’d been led to believe? The facts surrounding the bomb scare were so classified it’s likely that even some of President George W. Bush’s closest advisers were kept in the dark.

Dragonfire is Graff’s best guess at what might have happened in those fraught weeks after 9/11. Drawing on his extraordinary knowledge of the groups involved and how the characters within them operate, he re-creates the high-stakes search for the alleged bomb. His story—procedurally accurate and based on extensive interviews with several of the principal players—has the ring of actual events and the pace of a thriller. 

One thing is indisputable: The Dragonfire threat so deeply affected top U.S. officials that it accelerated and shaped America’s War on Terror, which in turn gave us the invasion of Iraq and the protracted war in Afghanistan, the calamitous end of which is still fresh in our minds. Whether the bomb was real or not, this little-known event, still shrouded in secrecy, sent shock waves through the U.S. government that reverberate to this day.