The Keys of Marinus The TARDIS arrives on the planet Marinus on an island of glass surrounded by a sea of acid. The travellers are forced by the elderly Arbitan to retrieve four of the five operating keys to a machine called the Conscience of Marinus - a machine capable of influencing all minds on the planet - of which he is the keeper. These have been hidden in different locations around the planet to prevent them falling into the hands of the evil Yartek and his Voord warriors, who plan to seize the machine and use its originally benevolent mind-influencing power for their own sinister purposes.
Dalek The Ninth Doctor and Rose Tyler arrive in 2012 to answer a distress signal and meet a collector of alien artefacts who has one living specimen. However, the Doctor is horrified to find out that the creature is a member of a race he thought was destroyed: a Dalek.