espionage

• Cloak and dagger

  This phrase refers to activities or situations characterized by secrecy, intrigue, espionage, and often danger.

• A honey trap

  A deceptive scheme in which a person is enticed into a compromising romantic or sexual situation, often for the purpose of espionage, blackmail, or other illicit gain.

• Sleeper agent

  A secret agent who is planted in a target country or organization and remains inactive for a long period before being activated for a specific mission.