The Dark Samurai (unproduced TV story)
The Dark Samurai was an unproduced story written by Andrew Smith for Season 21. It was submitted around 1983, and later dropped due to budgetary constraints.
The story would have been a pure historical set in 19th century Japan. The Doctor, Tegan, Turlough and Kamelion find themselves in the domain of a particularly cruel daimyo, but they manage to win him over and earn his respect. One of his allies believes he has become a Western sympathiser and sends word to the Shogun. In response, a force of samurai are deployed to level the domain and seize control.
The script would have been very expensive to make, due to the significant number of locations and characters featured within it, and the difficulty that would be faced in recreating the cultural iconography of shogunal Japan. Elements of this scripts were later used in the Big Finish story The Barbarians and the Samurai however.