England, the near future. A strange anti-matter creature arrives on Earth and attacks UNIT HQ. It seems to be specifically seeking the Doctor out - but why? With the Time Lords themselves unable to help, it seems the only person who can help the Doctor is himself - or selves...
Quest roles:
William Hartnell(The Doctor), Patrick Troughton(The Doctor), John Scott Martin(Kriz), Nicholas Courtney(Brig. Lethbridge-Stewart), John Levene(RSM Benton), Clyde Pollitt(Chancellor), Roy Purcell(President of the Council), Graham Leaman(Time Lord), Rex Robinson(Gebek), Patricia Prior(Mrs. Ollis), Denys Palmer(Corporal Palmer), Laurie Webb(Mr. Ollis)