Wendell Lawson has only six months to live. Not wanting to endure his last few months of life waiting for the end, he decides to take matters into his own hands and enlists the help of a delusional mental patient to help him commit suicide.

Dexter Riley is a science student at Medfield College who inadvertently invents a liquid capable of rendering objects and people invisible. Before Dexter and his friends, Debbie and Richard Schuyler, can even enjoy their spectacular discovery, corrupt businessman A.J. Arno plots to get his greedy hands on it. Slapstick hijinks ensue as Dexter and his pals try to thwart the evil Arno before he can use the invisibility spray to rob a bank.

Cole Thornton, a gunfighter for hire, joins forces with an old friend, Sheriff J.P. Hara. Together with an old indian fighter and a gambler, they help a rancher and his family fight a rival rancher that is trying to steal their water.