After an unremarkable interview, Circus agent George Smiley determines the subject of a standard security check—a civil servant in the Foreign Office named Samuel Fennan—poses no threat, nor presents any reason for suspicion of espionage.

Hours later, Samuel Fennan is found dead by suicide. Suddenly finding himself under intense scrutiny, Smiley realizes the Circus intends to blame him for Fennan's death. Rather than remain idle, Smiley begins his own investigation into the nature of the man's demise. What he finds is a tangled web of secrets that connects not only to East German activity in Britain, but also his own past.

The beginning of a body of work that The New York Times calls "extraordinary in its breadth, consistency, generosity and wit," John le Carré's 1961 debut introduces one of the most esteemed and iconic spies in the literary canon: George Smiley.