This was a routine wiretapping operation for the KGB's counterintelligence department, Department K.
---From the "first sentence"

Gordievsky, with his sturdy, athletic build, strode confidently through the bustling airport.
But a faint fear simmered inside. Oleg Gordievsky, a KGB veteran and loyal Soviet secret agent, was actually a British spy.

--- p.16

Oleg Gordievsky's life was the KGB itself. It shaped him, loved him, twisted him, ruined him, and later nearly killed him.

--- p.23

Upon his return to Moscow, he was ordered to report to work for the KGB starting July 31, 1962.
Why would he join an institution that enforces ideology when he was already beginning to question it? The KGB job was attractive because it promised the possibility of international travel.
The secret is how to seduce people.

--- p.37

Here, Oleg, along with 120 other trainees, learned the deepest secrets of Soviet intelligence activities.
Espionage and counterintelligence, recruiting and utilizing spies, legal and illegal spies, spies and double agents, weapons, unarmed combat and surveillance, the incomprehensible techniques and language of this strange profession.
Among the most important teachings was surveillance detection and evasion, which in KGB parlance was called proverka, or "dry cleaning."
--- p.39

The KGB's illegal spy network in Scandinavia was not elaborate.
A large part of Oleg's work was administrative, such as leaving money or messages in abandoned mailboxes, monitoring signal points, and maintaining covert contact with secret spies.
Most of the secret spies were people he had never met face to face and whose names he did not know.

--- p.51

Professionally, Oleg was climbing the KGB ladder smoothly.
But his inner self was speechless.
His two years in Moscow deepened his alienation from the communist regime, and his return to Denmark deepened his despair at Soviet snobbery, corruption, and hypocrisy.

--- p.80

One of the oldest tactics in the world of espionage is the "bait."
It is a strategy in which one side approaches someone on the other side, lures them into becoming an accomplice, gains their trust, and then exposes their identity.

--- p.91

The best way to test whether someone is lying is to ask them a question to which they already know the answer.

--- p.114

The Soviet Union was essentially a giant prison.
More than 280 million people were trapped within the heavily guarded borders, and over a million KGB agents and informants served as guards.
The population was constantly under surveillance, and the KGB, in particular, was subject to closer surveillance than any other sector or institution in Soviet society. The KGB's Seventh Department, the agency responsible for internal surveillance, had approximately 1,500 employees stationed in Moscow alone.

--- p.144

The problem with oiling your boss is that he or she may change into someone new.
In the end, a lot of oil was wasted.

--- p.168

Suspicion is born of propaganda, ignorance, secrecy, and fear.
In 1982, the KGB's London branch was one of the most suspicious places on Earth, suffering from psychological pressure and obsession, but the basis of that state of mind was largely fantasy.

--- p.206

The relationship between British and American intelligence agencies is a bit like that of brothers.
This is because they are close to each other but competitive, get along well with each other but are also jealous, and support each other but often fight.
Both Britain and the United States had experienced past incidents of communist infiltration into high-ranking positions, and both harbored persistent suspicions that they could not trust each other completely.

--- p.233

The Hall of Spies, the people who changed the world, is home to only a select few.
One of those people is Oleg Gordievsky.
He opened the door to the KGB at a historically crucial time, revealing not only what the Soviet intelligence agency did (and did not do), but also what the Kremlin was thinking and planning.

--- p.287

Back at his apartment, Gordievsky tried to interpret the day's events. The KGB had no taste for mercy.
Even if they knew even a little bit of the truth, he was dead.
But given that he had not yet been taken to the Lubyanka basement, it was clear that investigators had not secured any crucial evidence.

--- p.365

Gordievsky led a double life for over ten years.
It was a life of being a professional intelligence agent dedicated to the country while secretly being loyal to the other side.
The skill to manage this kind of life was also very good.

--- p.480

For Western intelligence agencies, Gordievsky's case has become a textbook example of how to recruit and manage spies, how to use intelligence to improve international relations, and how to rescue a spy in the most dramatic of circumstances.

--- p.534