Doctor Who: The Keys of Marinus (TV)

On the planet Marinus, the scientist Arbitan locks the Doctor, Susan, Ian and Barbara out of the TARDIS in a desperate bid to convince them to embark on a quest to find a lost set of keys. These keys power the Conscience of Marinus, a mighty computer which is Marinus' last hope against the onslaught of Yartek and his evil Voord. But many dangers lie between the companions and each key: hypnotic monsters, killer plants, ice zombies, and finally a charge of murder.