The Doctor, Romana, Adric and K9 encounter the enslaved time-sensitive Tharils, who lead them to a white void occupied only by the ruins of an old building and a spaceship - a dimension that might be the key to escaping E-Space.
It's been 10 years since John Connor saved Earth from Judgment Day, and he's now living under the radar, steering clear of using anything Skynet can trace.
When the Master steals the Time Lords' secret file on the Doomsday Weapon, they grant the Doctor a temporary reprieve from his exile on Earth to deal with the crisis.
The Time Lords send the Doctor and Jo on a mission to deliver a sealed message pod to an unknown party aboard a Skybase orbiting the planet Solos in the 30th century.
The TARDIS arrives on the unnamed planet of the Gonds, who are ruled and taught in a form of self-perpetuating slavery by the alien Krotons — crystalline beings whose ship, the Dynatrope, crash-landed there thousands of years earlier after being damaged in a space battle.
The Doctor, Jamie and Zoe return to Earth and become embroiled in the schemes of Tobias Vaughn. They meet up with an old friend, Colonel (now Brigadier) Lethbridge-Stewart, and some old enemies, the Cybermen.
Professor Emil Keller has created a machine that can pacify even the most dangerous of criminals. But when the Doctor and Jo arrive at Stangmoor Prison for a demonstration, things start to go horribly wrong - especially when they discover that the Doctor's old enemy the Master is responsible for the machine.
The TARDIS lands in a space museum on Earth in the late 21st century, where the Second Doctor, Jamie and Zoe learn that contact has been lost between Earth and the Moon.
Popular movie trailers from 1981
These some of the most viewed trailers for movies released in 1981:
Anton and his family moved into a high-rise building. In order for the new neighbors to accept his trumpet music, he has to perform a little "miracle" with the instrument.
The story of an unhappy, childless princess, her loving husband and the poor villagers threatened by a terrible disease, who finally received help from above.
When Dr. Indiana Jones – the tweed-suited professor who just happens to be a celebrated archaeologist – is hired by the government to locate the legendary Ark of the Covenant, he finds himself up against the entire Nazi regime.