Written by Gerry Davis. This story was submitted to the production office, sometime in 1974 and commissioned soon after. The story was reworked by script editor Robert Holmes into "Revenge of the Cybermen" after the production crew had reservations about it, though Davis still received the full credit. Big Finish Productions has announced an audio adaptation of this story, written by John Dorney for their Lost Stories range, which was originally scheduled to be released in January 2021 but was rescheduled to be released in March 2021.