This Week’s Book Review – Gray Day

I write a weekly book review for the Daily News of Galveston County. (It is not the biggest daily newspaper in Texas, but it is the oldest.) My review normally appears Wednesdays. When it appears, I post the review here on the following Sunday.

Book Review

‘Gray Day’ details uncovering a cyber spy


Mar 25, 2019

“Gray Day: My Undercover Mission to Expose America’s First Cyber Spy,” by Eric O’Neill, Crown, 304 pages, 2019, $27

In 2000, FBI agent Eric O’Neill’s career was in eclipse. He had married a German foreign national. She was from the former East Germany and viewed as a potential security risk. Germany might have reunified and the Soviet Union gone, but Russia was still there. Because of that he got tapped for the biggest case of his career.

“Gray Day: My Undercover Mission to Expose America’s First Cyber Spy,” by Eric O’Neill recounts what happens next.

Robert Hanssen was selling secrets to Russia and earlier the Soviet Union. The FBI needed to prove this beyond a reasonable doubt. They wanted him in prison. He had been betraying the United States for decades and his revelations had led to the execution of several spies working for the United States. He was going to retire in April 2001.

The FBI set a trap for Hanssen. They put him in charge of a new FBI cybersecurity group, offering Hanssen a new batch of secrets to sell. They wanted O’Neill to be his deputy, to spy on Hanssen. O’Neill agreed.

The book follows the effort to trap Hanssen, as seen through the eyes of O’Neill. Despite Hanssen’s new posting being an FBI deception, as O’Neill shows, it filled a desperate need. The FBI entered the 21st century with its computer technology mired in the early 1980s and organizational attitudes toward computers from the 1960s. Hanssen’s spying exploited that.

“Gray Day” (Hanssen’s code name in the investigation) shows O’Neill cope with the pressure of juggling an abusive boss (Hanssen), keeping up with his schoolwork (O’Neill was a law student) and keeping his marriage intact — while secretly investigating his boss.

The book reads like a John Le Carre spy novel, but the events happened. Some names are disguised. O’Neill walks readers through the methods the FBI used to weave a net around Hanssen, including success and failures. He also shows the personal cost to him. His marriage started unravelling due to the pressures of the investigation.

“Gray Day” is a book that keeps readers on the edge of their seat, and contains an important message about data security.

Mark Lardas, an engineer, freelance writer, amateur historian, and model-maker, lives in League City. His website is


2 thoughts on “This Week’s Book Review – Gray Day”

  1. Joe Conservative:
    I am looking forward to reading a 1st person account of this REAL Russian spy story (double agent, no less — the highest paid according to Sun Tzu) !!!

    It is a good read. Although I began to feel more concern over O’Neill’s marriage than over how Hanssen would get caught.  (In part because I knew he was caught.)


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