In a Meditation Centre deep in the Chiltern Hills, Mike Yates is in a contemplative mood. His years of faithful service to the United Nations Intelligence Taskforce have come to an abrupt end, and he is having to take his leave of the people he has come to think of as Family. When the Brigadier suggests that his former Captain take a holiday in Morocco, Mike finds himself embroiled in an exciting battle with an old enemy that could mean the end for UNIT, the Doctor and the World.

Notes: Read by Richard Franklin, The Killing Stone is set after Mike Yates leaves UNIT.

Time-Placement: the first part of the story, up to Mike's gallstone operation, takes place after the main events of Planet of the Spiders, in the three-week period on Earth in which the Third Doctor was returning from Metebelis 3. The climax presumably occurs before the Fourth Doctor leaves Earth with Sarah and Harry in the final scene of Robot; however, it's implied that the Doctor must return from deep space in order to deal with the problem, which suggests that this may occur later in his travels, at least for him.

Includes an interview with Richard Franklin.