• falls exactly on a Doctor Who episode
• falls during the Classic era's season 17
• features the 4th Doctor (Tom Baker, 1974-81)

The Doctor and the newly-regenerated Romana land on a strangely familiar planet and investigate the drilling that is going on there. The Daleks are searching for their creator, Davros, in the hope that he can assist them in their war with the Movellans. The Doctor has to reach the evil Kaled scientist before the Daleks, but just who can he trust?

Writer: Terry Nation
Director: Ken Grieve

More information at Wikipedia.