The color videotape of this episode was wiped by the BBC and it remained in the archives for 30 years only as a 16mm black and white telerecording. However, the Doctor Who (1963) Restoration Team were able to restore color to the episode using the new "chroma dots" technology for the serial's release on DVD in 2009.
Latep was originally named Petal. This was changed to avoid confusion with Patel from Frontier In Space.
This episode was watched by 10.1 million viewers on its original transmission.
This episode takes place on Spiridon in the 26th Century.