The series premiered in 1959.

Harold Wilberforce Clifton is a retired air force Colonel, who now works for the British Intelligence Service, MI5, as a detective solving crimes worldwide. He is a resourceful and (stereo)typical patriotic Brit with a stiff upper lip, but he also has a tendency to having a bit of a temper. The stories are of a humourous nature, and celebrities from the real world are occasionally included in small roles.