Gary Berntsen, longtime CIA operative and the field commander who cornered Osama Bin Laden in Afghanistan, writing with award-winning novelist Ralph Pezzullo, offers in this edge-of-the-seat thriller a terrifying vision of where the next threat to America may come from.

When a highly placed Iranian intelligence operative walks into a U.S. embassy claiming to possess explosive information, counterterrorism officer Matt Freed is dispatched to interview him and is warned of an impending attack on the United States that could kill millions. But is the man’s story precious truth or calculated fiction? Matt isn’t sure, but with a possible catastrophe looming in less than two weeks, his superiors reluctantly prepare for the assault.

Matt can’t leave it alone, though. With questions still lingering about what is really going on, he defies his superiors’ orders and launches his own investigation. As the clock ticks down, he searches frantically for the truth at an Afghan prison under siege, an abandoned Uzbekistan bio weapons facility, and a Moscow hospital where an arms dealer is dying of a mysterious disease.

Ultimately, Matt’s efforts brand him an out-of-control renegade, and he finds himself left out in the cold. Yet he may be the only one with the knowledge needed to avert unimaginable chaos.

From a counterterrorism warrior who has spent a lifetime thwarting those who would do us harm, The Walk-In is an exhilarating plunge into tradecraft and terror.

"This novel is what thrillers aspire to be. Authors Berntsen and Pezzullo deliver a story that steams and dances like water on a red-hot skillet. The Walk-In is Tom Clancy for our era."

—Jeffery Deaver, New York Times bestselling author of The Bone Collector, The Sleeping Doll and The Broken Window

"The Walk-In is packed with what so many books lack: authenticity.  This is a thriller full of thrills, and while you're page-turning and nail-biting, be comforted by the fact that what's in it is fiction.  At least, so far..."

—SJ Rozan, Edgar-award winning author of In This Rain

"Gary Berntsen knows scary stuff the rest of us can only guess at, and he shares some of his dangerous expertise in The Walk-In.  As in his previous collaboration with Ralph Pezzullo, the best-selling Jawbreaker, the result is a hurricane.  The Walk-In roars across the hotspots of the globe and right to our front door, and I couldn’t put it down."  

—Peter Spiegelman, award-winning author of Red Cat

Brimming with rare authenticity and high-stakes thrills, and conceived by a CIA insider turned bestselling author, "The Walk-In" shows a counterterrorist operative racing against time to authenticate a defector's tale of imminent mass destruction.

GARY BERNTSEN served for more than two decades in the Central Intelligence Agency. He operated at the highest levels in the Middle East and Latin America and led the CIA’s major counterterrorist deployments in East Africa following the attacks on the U.S. embassies in Nairobi and Dar es Salaam. In hunting down Osama Bin Laden, he also commanded the most successful CIA paramilitary team ever assembled, a tale spellbindingly told in the New York Times bestseller Jawbreaker. Berntsen is a recipient of the CIA’s distinguished Intelligence Medal and Intelligence Star.

RALPH PEZZULLO is a former journalist, an award-winning playwright, screenwriter, and poet, and the author of At the Fall of Somoza, Plunging into Haiti, and the mystery novel Eve Missing. His novel The Resurrection of Thomas Lear was a semifinalist for the Faulkner Prize.