October Men — Anthony Price

Without telling anyone, Dr. David Audley has slipped away on an unauthorized voyage to Italy. There is the immediate and ghastly suspicion--an occupational hazard in espionage circles--that he may have defected. Other British agents are put on his trail.

Meanwhile in Rome, the head of Italian Security, General Montouri, is no less interested in Audley's arrival. Particularly as it has already flushed from cover Montouri's hated enemy Ruelle, a "rogue" Communist who has been disowned by his party.

The lure for Audley has been a leakage of some extraordinary information. His investigation starts a chain reaction which he is powerless to stop and which becomes, for him, a matter of life and death.