A shipping disaster in the 19th Century has stranded a man and woman in the wilds of Africa. The lady is pregnant, and gives birth to a son in their tree house. Soon after, a family of apes stumble across the house and in the ensuing panic, both parents are killed. A female ape takes the tiny boy as a replacement for her own dead infant, and raises him as her son. Twenty years later, Captain Phillippe D'Arnot discovers the man who thinks he is an ape. Evidence in the tree house leads him to believe that he is the direct descendant of the Earl of Greystoke, and thus takes it upon himself to return the man to civilization.

After being released from prison on a bum charge, Harry Barber is out for payback to regain his lost two years. He's hired by Mrs. Malroux to fake the kidnapping of her stepdaughter (the daughter of a dying millionaire). He discovers that he is being set up on multiple levels and will soon face a longer sentence if he doesn't prove the truth.

Half man, half monkey, Chad was born in a lab and kept hidden from the world. A journalist, investigating a macabre mass-murder, discovers the mutant boy — a creature with the mind of a child and superhuman strength. But the reporter finds out the hard way that nothing, and nobody, can stand in the way of progress. (Re-titled for its American VHS release, "Monkey Boy" is an abbreviated film version of Lawrence Gordon Clark's 1991 mini-series "Chimera".)