In order to qualify to inherit the family fortune, the four heirs must spend the night in the family estate. However, during the night someone starts killing them off.

A scientific team in Mexico discover a pool of unusual baby "octopus-like" specimens. Gathering a few for analysis back at the lab, it is soon discovered that the critters belong to a gangly six-foot half man/half octopus-like creature, that's pretty angry and wants her 'babies' returned…

Rich momma's boy Wade Kingsley Jr. an Eastern dude, tries to follow in his murdered father's footsteps by returning to the West to partner up with Slim Moseley Jr.,the son of his father's former partner. Wade overcomes Slim's initial reluctance to accept him by using his fortune to buy a prize cow and new car to help Slim in his job as foreman on the Kingsley family ranch, currently under siege by a gang of outlaws called "masked raiders." Wade generously tries to pay off the ranch's mortgage with $15,000 of his own money, but unfortunately neither "pardner" realizes that respected banker Dan Hollis, the son of their fathers' murderer, is the leader of the gang.

Aliens come to Earth seeking scientists to help them in their war.