Doctor Who (1963): Terror of the Vervoids: Part One

In 2986 AD, aboard the space liner Hyperion III, Doctor and Mel arrive responding to a distress call; communications officer Edwardes is found incapacitated, and the Hydroponics labs are hiding strange plant pods. The Doctor and Mel begin investigating missing pieces: “Demeter seeds” have been stolen, and someone deep in the ship is trying to keep secrets. Suspicion mounts when a passenger whose identity seems familiar dies under strange circumstances.