The TARDIS crew arrive in London in the year 2164. There they see ominous signs that things are wrong, including an actual sign informing people that it is forbidden to dump bodies into the Thames. Glad to see someone was getting on that problem. Anyhow, it turns out that the Daleks have showed up and taken over the Earth. They plan to hollow out the caramel center and install an engine. Yes, indeed. Because that totally makes sense. So its up to the Doctor and friends to put a stop to this! The story here is good, and theres an epic chase scene involving a wheelchair that has to be seen to be believed. This is also the first Strange Daleks episode, where theyre embarking on a really weird plan (see also: The Power of the Daleks, Victory of the Daleks, Evolution of the Daleks and really almost every other Dalek story). It also proved to be popular enough to be turned into a movie with Peter Cushing playing Dr. Who, and Bernard Cribbins, best known as Donnas grandfather on the new series, playing a police officer. But whats really good about this story is the solid emotional core. The Doctor watches as his granddaughter falls in love with one of the rebels and, in the end, decides to leave her behind to set up a new life (which leads to a sequel we will discuss when we get to the 8th Doctor stories). He gives Susan a great farewell speech and, for the first time, a companion leaves the series.