The first appearance of The Master, Jo Grant and Mike Yates.
Nicholas Courtney suffered a bout of depression during filming. His condition was noted by Jon Pertwee and Barry Letts, who elected to excuse him from filming when necessary. In some scenes, he is played by a double or his lines are given to others.
The color master tapes of this four-part serial were wiped by the BBC in the 1970s and the BBC only held 16mm black and white telerecordings. The serial remained only in black and white until the 1990s, when the color signal from a domestic NTSC recording was used with the black and white telerecordings to create new color masters on D3 digital tape.
This serial was heavily criticised following transmission due to making a series of everyday items into horrific killing items, including a plastic chair, a troll doll, a telephone flex and artificial daffodils. Officers from Scotland Yard also complained to producer Barry Letts about the representation of killer Autons masquerading as policemen.