The realm of magic is being threatened by the realm of logic, so Carolinus, the green wizard decides to shield it for all time. Ommedon, the evil red wizard, stands in his way. Carolinus then calls for a quest that is to be led by a man named Peter Dickinson, who is the first man of both the realms of science and magic. It is Peters job to defeat Ommedon.

Perennially stoned Cheech and Chong tear through the city of Los Angeles, causing trouble wherever they go. After Cheech loses his job, the two pot enthusiasts head to the welfare offices where Cheech’s girlfriend, Donna, works. Instead of collecting unemployment, they find themselves thrown back on the streets, searching for a way to earn new income. But when Cheech’s cousin, “Red” Mendoza, arrives, things get even crazier.