After meeting by coincidence on a California highway, Cheech and Chong attempt to return to the United States in order to attend their party after being mistakenly deported to Mexico.
Cheech and Chong live in a run-down old house, where they cause a lot of inconvenience to their neighbor because of the overwhelming mess that the duo leaves behind, but soon an unexpected meeting of Chong with Cheech's cousin Red causes things to escalate.
After experiencing financial difficulties, Cheech and Chong, who own an ice cream truck, decide to start selling drugs in an attempt to realize their goal of owning an island, a guitar, and a luxurious lifestyle filled with ladies.
In between jobs as musicians and car wash employees, Cheech and Chong take on the duty of transporting a car from Chicago to Las Vegas. When they discover that the vehicle is carrying a substantial quantity of cash, their journey is put in danger.
After stepping in for Dolly Parton and Burt Reynolds at a film festival in Amsterdam, Cheech and Chong spend their time there in a limousine, a fancy hotel room, and an important press meeting.
The film's events revolve around twin brothers Louis and Lucien, who can weirdly feel each other's wounds as if it is their own. However, the twin brothers decide to revolt against a tyrannical and unjust ruler in France.