Despite its title, this outstanding novel is not primarily a typical action-packed spy thriller. Rather it is a psychological examination of how the childhood and later life experiences shaped the protagonist, Msgnus Pym, into a man perfectly suited to be a highly successful spy -- one who is capable of compartmentalizing his life according to the role he is playing, one who is able to charm and please all people, one who can rationalize and self-justify his betrayal of those who trust him. The title might as well have been "A Perfect Psychopath," because the character traits are much the same.
As the story begins, Magnus Pym has disappeared and M16 (the British equivalent of the CIA) is frantic to find him. If he has been compromised, his whole network of spies and informants must be warned to go into hiding. The American intelligence people are also alarmed, because they have begun to suspect him as a double agent and he knows some of their secrets. His wife is worried because she loves him. As it turns out, Magnus has holed up in his own private safe house and is writing his life story in a letter to his son Tom and his M16 mentor, Jack Brotherhood. The bulk of the novel is his account of growing up motherless as the son of a charming con man who alternately lavished attention on him or abandoned him.
This is an extraordinary novel, on many levels. I have never read a more effective portrayal of how the survival traits developed because of childhood trauma can adversely affect a person. I have seldom read a more well written book. It is subtle, always showing rather than telling. And it is highly suspenseful, despite its lack of James Bond-type derring-do.
Interestingly, in the introduction to the novel the author says that he based the father of the protagonist on his own father. Since the character attempts to exorcise his inner demons by writing, and since Le Carre' was himself once a member of M16 who turned to writing, one can only assume that his character's psyche is a reflection of his own.
I highly recommend this book, even to those who do not ordinarily read in the spy genre.