Upon returning to civilian life in New York, Paul Haydn discovers that the ideological threats he witnessed in post-war Berlin have infiltrated his own professional and personal circles. Haydn, a veteran with specialized counter-propaganda skills, finds himself targeted by a clandestine network attempting to ruin his reputation and discredit his former love. As he navigates the shifting loyalties of his colleagues, he must determine who is a genuine ally and who is a covert operative for a sinister political agenda. The narrative unfolds through a tense, methodical investigation that mirrors the psychological warfare Haydn previously encountered abroad.

This novel reflects the author's signature approach to the espionage genre, emphasizing intellectual rigor over explosive action. The narrative structure relies on the slow accumulation of evidence, mirroring the protagonist's own realization of the encroaching political threat. Readers often note the book's historical significance as a document of early Cold War anxieties regarding domestic subversion. The prose maintains a clinical detachment that heightens the sense of unease as the protagonist uncovers the hidden patterns of his adversaries.