Bishop, head of BISHOP and Unwin's superior, Blake, a junior BISHOP operative, and Mrs Appleby, Unwin's housekeeper, who is unaware of Unwin and Matthew's double life as spies. Prior to the events of the series, the scientist Professor Humbert invented the Minimiser, a device capable of shrinking people or objects to one third of normal size. When Humbert died it was inherited by Unwin, who conceals it inside a large book. The device is regularly used on Matthew, who is reduced to a height of to enable him to carry out covert reconnaissance where any normal-sized person would be noticed. (In this manner, the puppet is shown to interact with life-sized sets and live actors whose faces are kept out of shot.) On occasion it is also used to shrink enemy agents, literally bringing them down to Matthew's size. Unwin carries the miniaturised Matthew around in a specially-adapted briefcase that can open from the inside and contains field equipment such as a periscope. During missions, the agents communicate via earpiece transceivers (with Unwin's disguised as his hearing aid). Their primary mode of transport is a revamped 1917-issue Ford Model T called Gabriel, which is capable of speeds exceeding . If challenged by law enforcement or enemy agents, Unwin spouts a form of gibberish to confuse the opposition and cover for Matthew. While most of the Supermarionation series are set in the future, the events of The Secret Service take place in the then-present day. The episodes "Errand of Mercy" and "The Deadly Whisper" are respectively set on 3 February 1969 and 24 May 1969. Gerry Anderson biographers Simon Archer and Marcus Hearn argue that the setting is ambiguous: they believe it to be "sometime in the near future" but note that the world of The Secret Service sees "Morris Minors negotiate leafy country roads while space-age helijets patrol the skies", ultimately concluding that the series is so fantastic that it "isn't set in the real world at all." Episodes Production After the completion of Joe 90, producer Gerry Anderson decided to create another espionage series. This would feature an English village as the home of its spy protagonist, an eccentric parish priest. Anderson hired Stanley Unwin to voice the character (which was ultimately also sculpted on and named after him) after unexpectedly meeting Unwin at Pinewood Studios while the comedian was completing dubbing work on the film Chitty Chitty Bang