Don Houghton was inspired by A Clockwork Orange (1971) to write a story in which a machine alters criminal minds with the ostensible aim of rehabilitating them. He was concerned that this would not be substantial enough to flesh out six episodes, however, and adopted the suggestion of his wife Pik Sen Lim, of including a subplot involving intrigue at an international peace conference.
The master videotapes of this serial were wiped by the BBC in the 1970s and although colour versions were sold overseas, only 16mm black-and-white film prints were retained by BBC Enterprises. It was released in black-and-white on VHS. However, for the serial's DVD release in 2013, this episode was manually restored to colour and all subsequent episodes were restored to colour using the chroma dots information which had been discovered in the film prints.
Andy Ho was cast as Fu Peng did film some scenes but was replaced by Kristopher Kum because the production team were displeased with Ho's acting.
The Master's pseudonym was originally Emil Dalbiac before the surname was changed to Keller, while the Keller Machine itself was conceived as the Malusyphus box.