Retired commander of the United Nations' Intelligence Taskforce, and long-time associate of the mysterious time traveler the Doctor, Brigadier Alistair Lethbridge-Stewart faces the toughest battle of his military career when he is embroiled in a plot unwittingly set in motion by university chancellor Victoria Waterfield, herself a former companion of the Doctor, to take over the Earth by an evil alien entity called the Great Intelligence, aided by its ferocious robot Yeti cohorts. Can the Brigadier defeat this menace to the Earth without the Doctor's help?

The Stranger and Miss Brown visit Majus 17 a intergalactic tourist paradise. However, they soon discover all is not as it seems - as they find decaying corpses in the woods and bathers are being swallowed by an angry sea.

A beautiful medical student travels to London to investigate the mysterious murder of her identical twin sister. Taking on her sister's identity, she gets closer and closer to the killer who is determined to finish the job once and for all.