In the mining village of Killingworth, Northwest England, in the 19th Century, miners are being gassed in the washhouse and transformed into thugs and vandals. They have been attacking men and machinery and are condemned as Luddites. The Doctor (Colin Baker) and Peri (Nicola Bryant) arrive in the village, trying to track down some time distortion they detected, and the Doctor notices a strange red mark on the neck of one of the rampaging miners. He presents himself to Lord Ravensworth (Terence Alexander), the local landowner.
It seems the renegade Time Lord called the Master (Anthony Ainley) is there, along with a Time Lady called the Rani (Kate O’Mara). Posing as an old woman who runs the washhouse, she is a gifted chemist. They anaesthetize the miners and take from their bodies the neurochemicals that produce sleep, which they are gathering for the planet Miasimia Gloria. The Rani rules there and with the Master, they have, with their dark experiments, destroyed sleep. When the Master discovers the Doctor meddling in his affairs, he persuades the rampaging miners to throw the TARDIS down a mineshaft.
The Doctor dresses like a miner and enters the washhouse. The Rani traps him, but he challenges her. He knows she has been coming to Earth for centuries for her evil harvest. The Doctor is strapped to a trolley and set rolling toward the mineshaft. Happily, the inventor George Stephenson (Gawn Grainger) saves him. The Doctor and Peri visit him in his cottage. He is planning a meeting of the great geniuses of the 19th Century, and the Doctor is worried.
The Master takes control of Stephenson’s young aide, Luke Ward (Gary Cady), telling him to kill anyone who tries to prevent the meeting. The Master wants to use the best minds of the Industrial Revolution to speed up Earth’s scientific development and then seize control of the planet. He promises the Rani she can come and harvest her brain chemicals any time, though they are villains and don’t trust each other.
The Doctor returns to the washhouse, avoids the booby traps, and finds a way into the Rani’s TARDIS. As the Doctor examines the dinosaur embryos inside, she summons her TARDIS and he comes along for the ride. He overhears her telling the Master that she has laid bizarre landmines in Redfern Dell nearby. The Doctor sneaks out and returns to Ravensworth. Stephenson and Luke have been acting strangely.
Peri is using her botanical knowledge (Where did that come from? I thought she was an archaeologist.) to make a sleeping draught for the miners, but she must go to Redfern Dell for plants. The Doctor saves her, but Luke steps on a mine and is turned into a tree. (That’s right.) The Doctor gets control of the Master and the Rani with the Master’s Tissue Compression Eliminator. Peri is watching them, but they escape into the Rani’s TARDIS, except that the Doctor has sabotaged the navigation system and velocity regulator, and the ship goes out of control. One of the jars with a T-Rex embryo breaks and affected by the time spillage, a T-Rex begins to grow. The Master and the Rani are flattened against the wall by centrifugal force, watching the carnivore develop quickly.
The Doctor and Peri give Ravensworth, who has recovered the TARDIS, the brain fluid which will cure the miners, and they slip away, astonishing the inventor as the TARDIS fades from view. Who was that time-traveller anyway?
The story was filmed in the Blists Hill Victorian Town, the Blists Hill Open Air Museum, Granville Colliery Spoil Heaps, the Ironbridge Gorge Museum, and the Coalport China Museum, all in Shropshire. It is the first story since The Gunfighters, with the First Doctor William Hartnell, in 1966, to feature real historical characters. It was well-received, for a change. The Rani’s TARDIS is gorgeous, the period settings fascinating. The direction by Sarah Hellings and the haunting music by Jonathan Gibbs were praised. This was the last Doctor Who story to be directed by a woman until Blink, with David Tennant in 2007, directed by Hettie Macdonald. Many of the historical details in the story were a bit shaky, but what else is new? Thomas Telford, Michael Faraday, Humphry Davy, and Marc Brunel are to attend George Stephenson’s meeting.
The Rani was exiled from Gallifrey because her giant mice ate the Lord President’s cat. And because she is evil, though I’m not sure how you can tell in Gallifrey. She has been messing with Earth during the Trojan War, the Dark Ages, and the American War of Independence, apparently. The Rani’s TARDIS will likely be flung beyond the Milky Way, if not to the edge of the universe, but she and the Master are unlikely to live that long. But there is no explanation of how he got out of his last inevitable doom. The Doctor seems to be mellowing a little bit at last. His arrogance is mixed with a bit of wit and compassion. The best cameo in the story, to my mind, is a replica of Stephenson’s Rocket, an 0-2-2 built for the Raven Hill steam-train trials in October 1829. Built in Newcastle-upon-Tyne, it won by hauling 20 people at a dizzying 15 MPH. Unfortunately, the Member of Parliament for Liverpool was run over and killed.