Danger Mouse is a secret agent with the British Secret Service, and together with his sidekick Penfold is repeatedly ordered by Colonel K, the head of the Secret Service, to save the world.
They work underneath Scotland Yard on Baker Street in London, hidden inside a red pillar box. Their arch-enemies are Baron Silas Greenback and his criminal organization, who try to achieve world domination by unconventional means such as stealing all famous buildings, or creating giant robots, etc.
A special role is played by the off-screen narrator, Isambard Sinclair, who accompanies the action by commenting on it sarcastically, talking to the characters or musing about his private life.
