In the heart of the Cold War, British intelligence learns of a high-stakes Russian cipher machine, the Lektor, which MI6 is determined to obtain. James Bond, agent 007, is dispatched to assist in its defection, being lured to Istanbul under the pretense of a tantalizing offer from a beautiful Soviet consulate clerk, Tatiana Romanova, who claims she's willing to betray her country for love. Unbeknownst to Bond, this is an elaborate trap set by SPECTRE, an independent criminal organization seeking revenge on Bond for his previous disruption of their activities. The plot is orchestrated by SPECTRE's Number 3, former KGB operative Rosa Klebb, who recruits a psychopathic killer, Donald 'Red' Grant, to shadow Bond and execute him after the Lektor is stolen.

Upon arrival in Istanbul, Bond connects with ally Kerim Bey, head of the local British intelligence station, to navigate through the city's risks and mysteries. Their journey is fraught with peril as they encounter enemy agents and the tensions between the local Romani communities and the Bulgarian secret police. As Bond and Bey work together to secure the Lektor, they strive to remain one step ahead of their adversaries, including Grant, who secretly follows Bond, waiting for the opportune moment to strike. With the various factions converging upon them and trust in short supply, Bond must use his wit and skills to outmaneuver both the Soviets and SPECTRE's menacing operatives.