Sarah-Jane Smith returns home to her Aunt Lavinia,who is actually on a lecture tour in America and again faces another Christmas holiday after grueling international journalism without the presence of her family. Upon arriving she encounters her aunts ward,a student named Brendon and a mysterious package that has apparently been laying waste in the family attack for several years now. Upon opening the box,the discover it is a gift from the doctor of K-9 Mark III. Though immediately fascinated by the unique gift,Sarah and Brendon soon find more to worry about. Sarah is concerned about her aunts abrupt lecture tour during the holidays. Not only that but,upon investigating on her own among the village locals discovers her Aunt's gardener George Tracey and his son Tracy behaving very mysteriously about some mysterious constructs near their green houses.
This is corroborated when,upon going to investigate himself,Brendon is attacked by Peter after being warned by him to stay away from the area. And the accompanying K-9 is promptly blamed for the damage done in the scuffle. In her bewilderment Sarah presses her investigation on the locals with the help of K-9 discovers debate about the possibility of a witch coven in the area. In the end Brendon is abducted from his bedroom,driving Sarah to take K-9 on a direct investigation. His study of maps of the local area,as well as Sarah's discovery on witchcraft texts in the house library lead them to a local chapel where they discover Brendon surrounded,in fact by a ritual coven. After K-9 confronts them with his lasers,Sarah is able to finish them off in defense of Brendon before spending Christmas with her Aunt's friends,whom she'd previously suspected of being part of the coven.
This story was produced in 1981 as a one off program by John-Nathan Turner,who hoped to spin the successful characters of K-9 and Sarah-Jane Smith together in their own series. This story set about creating a series of new characters for the audience to connect to,such as Brendon Richards. The series Turner was hoping to promote never in fact materialized. And this in fact remained a one off. In 2008 it was released on the bonus disc of the Doctor Who story The Invisible Enemy in which K-9 first appeared. In the end,this story is really more of a vehicle for Elizabeth Sladen's Sarah-Jane Smith. Possessing more refined self assured attitude than she had even had while travelling with the doctor,and in a position to take charge of her own life this story really pushed the envelope,though all to briefly in this particular case,in terms of establishing Sarah as a vital stand-alone character.