Written by Douglas Camfield, this four-part story was commissioned on 22 January 1976. The story would involve the Doctor and Sarah arriving in North Africa at an isolated French Legion outpost. This has become the battleground for a fight between two alien races, the Skarkel and Khoorians. The story was planned to write out the character of Sarah and would see Sarah killed by one of the aliens. The first script was submitted on 9 February 1976 and removed from the series schedule in April 1976. Camfield would continue to work on the scripts, delivering the final part on 24 September 1976, but the production team were no longer interested in pursuing the story.