Doctor Who: The Ambassadors of Death

Seven months after it left the red planet, Mars Probe 7 still hasn't returned to Earth. The Doctor and Liz Shaw join the investigation as a second capsule, Recovery 7, is sent to discover what has happened. But when it returns, something is terribly wrong with its three astronauts...

The space-suited figures are kidnapped and Brigadier Lethbridge-Stewart leads UNIT in a rescue attempt - whilst Liz finds herself at the mercy of dangerous fanatics. Only a solo space flight by the Doctor can break the deadlock surrounding the crew of Mars Probe 7. Closer to home, however, a deadly fear threatens a catastrophic end for the entire Earth.