When scientists in the Antarctic uncover a mysterious seed pod, the Doctor is called in to investigate. He soon realises it is extraterrestrial and extremely dangerous. At the same time, however, ruthless millionaire plant-lover Harrison Chase has learned of the find and decides he must have the pod for his collection of rare and beautiful flora. Meanwhile the pod itself harbours intelligent life with sinister plans of its own…
Length 150 minutes
Tom Baker | Elisabeth Sladen | Tony Beckley | Kenneth Gilbert | Michael Barrington | Sylvia Coleridge | John Challis | Mark Jones | Seymour Green | Michael McStay | Hubert Rees | John Gleeson | Ian Fairbairn | John Acheson | Ray Barron | Alan Chuntz | David Masterman | Harry Fielder