Tom and Elisabeth Sladen as Sarah Jane Smith in the jungles of Zeta Minor.
Picture © BBC
PLANET OF EVIL
September – October 1975
“You and I are scientists, Professor. We buy our privilege to experiment at the cost of total responsibility.”
Doctor to Professor Sorenson, episode 4
Leaving Harry to return to London via British Rail, the Doctor and Sarah’s journey back to the capital aboard the TARDIS is interrupted when they receive a distress call coming from Zeta Minor, a planet on the very edge of known space. Here, on the fringes of creation, borders between the universes of matter and anti-matter are very thin. Recent excavation activities by a geological survey party – hunting for new energy sources – has ruptured these borders, leading to a series of grisly deaths, and escalating peril for a space party sent to rescue this expedition.
The Doctor deduces that, just as the known universe has a binding intelligence, so the universe of anti-matter is driven by a darker, more savage energy that, once unleashed, will infect all who come into contact with it. For some in the expedition it is already too late. As the body count rises, the Doctor must convince the leading geologist, Professor Sorenson (Frederick Jaeger), that only the return of any harvested samples to their point of excavation, and the sacrifice of Sorenson’s own infected body can restore the balance and reseal the rift between the two universes.
But Sorenson’s regression from man into anti-man is now embedded and underway. Even as the survey’s rescue ship attempts to escape from Zeta Minor, the savage monster that was Sorenson begins stalking the decks and cabins… Somehow the Doctor must prevail against an enemy born from the forces of creation.