Gray Day Book Cover

Gray Day

“An adrenaline-laced memoir … as compuslively readable as any thriller.”

Eric O’Neill, cybersecurity expert and former FBI “ghost” tells the thrilling story of how he helped take down notorious FBI mole Robert Hanssen, the first Russian cyber spy.

A tension-packed stew of power, paranoia, and psychological manipulation, Gray Day is also a cautionary tale of how the United States allowed Russia to become dominant in cyberespionage–and how we might begin to catch up.

About the Book

Gray Day: My Mission to Expose America's First Cyber Spy

Eric O’Neill was only twenty-six when he was tapped for the case of a lifetime: a one-on-one undercover investigation of the FBI’s top target, a man suspected of spying for the Russians for nearly two decades, giving up nuclear secrets, compromising intelligence, and betraying US assets.

With zero training in face-to-face investigation, Eric found himself in a windowless, high-security office in the newly formed Information Assurance Section, tasked officially with helping the FBI secure its outdated computer system against hackers and spies–and unofficially with collecting evidence against his new boss, Robert Hanssen, an exacting and rage-prone veteran agent with a disturbing fondness for handguns.

In the months that follow, Eric’s self-esteem and young marriage unravel under the pressure of life in Room 9930, and he questions the very purpose of his mission. But as Hanssen outmaneuvers an intelligence community struggling to keep up with the new reality of cybersecurity, he also teaches Eric the game of spycraft. Eric will just have to learn to outplay his teacher if he wants to win. 

Artboard Copy 23

Gray Day: Available Everywhere Books Are Sold

Praise for Gray Day

Fans of spy fiction and true crime will find plenty to enjoy in O’Neill’s account.
Gray Day is a book you’ll stay up all night with.
Gray Day is a well-written and suspenseful story about an odd spy and the young man who helped take him down.
An adrenaline laced memoir…as compulsively readable as any thriller.
This is an interesting and compelling read. And unlike Tom Clancy spy novels, this is a work of non-fiction.
Gray Day is both a real-live tension packed thriller, and a persuasive argument for traditional intelligence work in the information age.
Bruce Schneier
New York Times bestselling author of Data and Goliath and Click Here to Kill Everybody
If Robert Ludlum spitballed an espionage story with a Russian hacker, they might have conjured up with something as wild and riveting as GRAY DAY. Except that this yarn, incredibly, is true. An enthralling spy tale that feels ever more relevant with each passing day.
Dave Howard
Author of Chasing Phil: The Adventures of Two Undercover Agents with the World’s Most Charming Con Man
Gray Day is a fascinating read about catching infamous spymaster Robert Hanssen, who turned over classified materials to the Russians. You can’t help but root for Eric as he tells his story of spying on the spymaster. I recommend this gripping book to all audiences, especially computer geeks and those interested in cybersecurity.
Kevin Mitnick
New York Times bestselling author of Ghost in the Wires and The Art of Invisibility
With resolute doggedness, shrewd psychological instincts, and the sheer guts to make critical split-second decisions, rookie agent Eric O’Neill helped to turn the tables on his own boss—one of the most dangerous traitors of our time. In GRAY DAY he weaves together his personal and professional stories with all the skills of a seasoned novelist. The result is a thrilling, page-turning brew worthy of Hollywood—only better because it’s real.
Elisabeth Elo
Author of Finding Katarina M.
An adrenaline-laced memoir… as compulsively readable as any thriller. O’Neill has a knack for ratcheting up tension so that foregone historical conclusions, such as Hanssen’s capture, feel like white-knuckle cliffhangers… O’Neill’s page-turner deglamorizes undercover work while conveying the uncertainty, stress, and excitement that accompany a successful investigation.
Author Eric O'Neill's Headshot

About the Author

Eric O’Neill is the author of Gray Day and the subject of Universal Studios’ feature film, Breach. 

Eric O’Neill’s career began in the FBI’s counterintelligence trenches as an undercover operative. His undercover work brought down Robert Hanssen, the most notorious and damaging spy in United States history. Since then, Eric has spent decades as a national security attorney, corporate investigator, and national cybersecurity strategist.

He speaks to thousands each year across the globe, inspiring audiences to protect themselves and giving them actionable tools to do so. People may be more motivated first by helping themselves and their organization.

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