The podcast episodes explore the role of double agents in various historical events, particularly their use during World War II and the Cold War.

Key examples highlighted include the use of double agents like 'Garbo' (Juan Pujol) to mislead the Germans about the D-Day invasion location in D-Day: The Tide Turns and Introducing: D-Day: The Tide Turns - Episode 1, as well as the story of Oleg Lyalin, a KGB agent who was blackmailed into becoming a double agent for MI5 in The Spy Who Saved MI5 | The Pressure Cooker and The Spy Who Saved MI5 | The Spider and the Fly.

The episodes also touch on the personal sacrifices and moral ambiguity faced by double agents, as seen in the case of Oleg Gordievsky, a KGB spy who defected to MI6 in #182: The People Who Spy On Us (KGB & MI6 Spy Kidnapping).