Unknown to the Doctor, his TARDIS has been dragged off course by the Master who plans to destroy his arch enemy once and for all, and pervert the course of history.

But also present is the Rani, another exile from Gallifrey, who is conducting her own evil experiments on the humans of the nineteenth century. Soon the Doctor discovers that the female of the species is far, far deadlier than the male...
 

The TARDIS is drawn off course and materialises close to the Killngworth coal pits in the north of England during the early nineteenth century. The Luddite rebellion is in full swing as workers fight to prevent their jobs being taken by machines.

The Doctor and Peri quickly learn that they are not the only time travellers in the area - the Doctor's old adversary, the Master, is attempting to disrupt a meeting between some of Britain's foremost scientists, including George Stephenson and Michael Faraday. The violence among the miners is part caused by the interference of another renegade Time Lord, the Rani, who is extracting chemicals from their brains to serve her own nefarious purposes.

The Doctor must avoid the vicious attacks of the mortals, halt the Rani's immoral experimants and thwart the Master's plot to hijack the industrial Revolution...

Originally transmitted 2 February to 9 February 1985.

Running time: 90 mins approx.

Produced by John Nathan-Turner

Directed by Sarah Helings

Cover Illustration by Colin Howard