影片改编自英国作家沃尔特·司各特中世纪骑士文学代表作《艾凡赫》（1819），描述效忠约翰王子的诺曼人与效忠狮心王李察的萨克逊人互相对抗。萨克逊英雄艾凡豪卖力地筹集赎金，希望将被俘的李察从诺曼人手上赎回，因而跟恶棍盖利伯发生了连场恶斗。期间，艾凡豪也跟两个英丽女子路文娜及丽贝嘉发生了三角恋爱的冲突，构成了一部热闹动人的电影。

The TARDIS materialises in England in the 1970s and the time travellers meet a girl named Isobel whose uncle, computer scientist Professor Watkins, has recently gone missing. The Doctor offers to help track him down, starting at the place where he last worked - the London HQ of International Electromatics, the world's major supplier of electronic equipment. His initial suspicions about IE's managing director, Tobias Vaughn, are confirmed after he becomes reacquainted with Lethbridge-Stewart, now promoted to Brigadier and in charge of the British branch of the United Nations Intelligence Taskforce (UNIT), and learns that there have been other disappearances at IE premises. He discovers that Vaughn is in league with the Cybermen in a plan to invade Earth, but is also plotting against them with the aim of seizing power for himself. Watkins is being forced by Vaughn to develop the cerebration mentor, a machine designed to generate emotional impulses as a weapon against the Cybermen. The Cybermen immobilise most of Earth's population - sending a hypnotic signal through special circuits incorporated in all IE equipment - and launch their invasion. The Doctor has managed to protect himself and his friends from the signal and - with help from an embittered Vaughn, who is killed during the fighting - the invasion is eventually defeated.

S13E21-26 Two alien seed pods are found buried in the Antarctic permafrost and the Doctor realises that they are from a Krynoid, a form of plant life that infects and transforms all animal life on planets upon which it becomes established. One of the pods infects a scientist at an Antarctic base but the developing Krynoid is destroyed by a bomb set by two men, Scorby and Keeler, who have made off with the other pod for their boss, eccentric plant collector Harrison Chase. At his mansion in England Chase arranges for the pod to be opened under controlled conditions while a human host - Sarah - is held nearby. The Doctor rescues Sarah, but Keeler is infected. Keeler's transformation into a Krynoid is accelerated by Chase, who has him fed with raw meat. The creature escapes and goes on the rampage, rapidly growing to giant proportions. Chase decides to turn the Doctor into compost by feeding him into a pulverising machine. The Time Lord escapes, but Chase falls into the machine and is killed. UNIT have meanwhile been called in, and they arrange for the Krynoid to be bombed before it can spread its pods across the Earth.