One of the many notorious 70's "unknown" documentaries, The Mysterious Monsters covers topics such as Bigfoot and the Loch Ness Monster. Pictures, sounds, and videos of these two monsters are examined by Peter Graves, the host. Psychics, hypnotism, and the history of Bigfoot in many ancient cultures is also scrutinized.

Major Jim "Lance" Lansing, an American ex-pilot of the U.S. Air Corps, returns to Scotland after the war and finds much trouble in the glen where he settles because of the high-handed activities of the local laird, Sandy Mengues, a wealthy South American who, with his daughter Marissa, has returned to the land of his forefathers. Led by Lansing, the people eventually prevail upon Mengues to restore peace to the glen, but not before a brief and unconvincing fight between Lansing and Dukes, the Mengues foreman. Written by Les Adams