Pedro lies passed out on his couch at home. When he is awoken by children watching cartoons, he stumbles to the bathroom and accidentally urinates into the laundry basket instead of the toilet. Meanwhile in Beverly Hills, the parents of “The Man” confront their son as he makes a banana smoothie. His father threatens to send his son to military school if he doesn’t get a job. Ignoring his parents, the Man wanders out of the house and drives off in one of their many cars. After the car breaks down on the highway, the Man stuffs his shirt so he appears to have breasts and hitchhikes. Thinking The Man is a woman, Pedro pulls over his car, "The Love Machine," but becomes angry when he sees that the Man has tricked him. The Man apologizes, and Pedro allows him to load all of his stuff into the car, including a drum set. Pedro drives off speeding, and The Man panics, asking to get out of the car. Pedro offers him a marijuana cigarette to relax, but the Man makes fun of it for being too small, pulling out his own marijuana cigarette that is the size of a burrito. Pedro tells The Man about all the other drugs he has taken in the past. The Man explains that his marijuana is part "Maui Wowie" and "part Labrador": after his dog ate his marijuana supply, the Man collected his dog's excrement and used the defecated marijuana in the cigarette they are smoking now. Stopping the car on the side of the road, Pedro is alarmed by the potency of the marijuana cigarette. However, after the Man gives Pedro some pills for relaxation, the Man realizes he accidentally gave him the hallucinogenic drug, LSD. As Pedro's anxiety grows, the Man encourages him to chant “Om” for relaxation. Once he has calmed down, Pedro laughs uncontrollably. Seeing a police officer approach, the Man swallows the rest of his LSD. Although Pedro distracts the officer by telling jokes, the Man throws up all over Pedro and they are arrested. In court, Pedro and the Man are too high to pay attention to the proceedings. That night, Pedro brings the Man to his house and lets him sleep over. The next day, Pedro introduces the Man to his band, and the group accepts him as their new drummer even though the Man rejects the new costumes provided by their friend Curtis. Later, the Man and Pedro leave the house in search of more marijuana. When the search proves unsuccessful, Pedro suggests they go to his cousin Strawberry’s house but warns the Man that Strawberry is a Vietnam War veteran and can behave strangely at times. He also warns The Man not to stare at Strawberry’s birthmark, but when the Man meets Strawberry, he can’t help but stare at the huge birthmark on his face. Learning that Pedro wants to buy marijuana, Strawberry says he knows where they can get some, but the Man cannot come because he is a stranger. Staying behind at Strawberry’s house, the Man accidentally knocks over some Ajax cleaning powder, and a woman wanders in. Mistaking the powder for cocaine, the woman snorts it all. Hiding in a laundry van, a group of narcotics officers – Sergeant Stedenko, Harry, Clyde and Murphy – stake out Strawberry’s house. Meanwhile, as Pedro and Strawberry ride together on his motorcycle, Strawberry experiences a Vietnam War flashback and jumps off. Pedro crashes, but gets back up and notices the police outside Strawberry’s house. A loud party inside Strawberry’s house distracts the Man, who cannot hear Pedro over the phone when he calls to warn him about the police. Listening in on the wiretapped conversation, the officers hear the Man tell Pedro that Strawberry’s house is full of drugs. Raiding the house, the police arrest several people who are on drugs. Dressed as a repossessor, Pedro arrives and sneaks the Man out of the house. After they buy marijuana from Curtis, Pedro, the Man and the band smoke it all, but the Man complains that he is still sober. Pedro notices more police but quickly realizes they are only immigrations officers. Since his cousin is getting married in Tijuana, Mexico, he called immigration to report himself so that everyone could get a free ride to Mexico. Pedro and the Man are deported with the rest of Pedro's extended family. While in Mexico, Pedro’s uncle asks Pedro and the Man to pick up a van at his upholstery factory and drive it back into the U. S. Meanwhile, Stedenko briefs the narcotics squad on a new technology being used to smuggle marijuana: “fiber weed,” a liquid marijuana spray that can be turned into plastic and used to build things like furniture. Stedenko identifies a local upholstery factory that may be using fiber weed, which happens to be the same factory where Pedro and the Man have just arrived. Unaware that the van they are driving is made entirely of fiber weed, Pedro and the Man drive to the border check point. There, the Man tosses his massive marijuana cigarette into a car full of nuns. Across the street, newscaster Toyota Kawasaki films a news report on the police search for a vehicle made of marijuana. Back at the checkpoint, the police seize the nuns’ car, allowing Pedro and the Man cross the border. However, when the Man stops to use the bathroom at the border patrol office, a police dog sniffs out the marijuana van and suddenly dies. Pedro and the Man drive off before the police learn that they arrested the wrong people and are told to look for two hippies in a green van. Stedenko and his men realize they just missed them, and jump in their car to give chase. Unaware that the police are after them, Pedro and the Man pick up two female hitchhikers, Jade East and Debbie. The girls tell Pedro about a "battle of the bands" happening at The Roxy that evening, and Pedro decides they should compete. The Man reluctantly agrees but insists they smoke marijuana first. Promising that they know someone who has drugs, Jade and Debbie lead the group to a police station. There, a police dispatcher named Gloria takes the girls into a bathroom to give them drugs. As Pedro and the Man toy with the police radio, they unwittingly prank Stedenko, who is on his way to the station. Although Gloria tells Jade and Debbie about the marijuana van the police are looking for, the girls have no idea they’ve been riding in it. Back on the road, a motorcycle officer pulls over the group but inhales marijuana smoke from the van’s tail pipe as he approaches. By the time the officer reaches the van, he’s forgotten why he stopped them and lets them go. Having received a call from Pedro, Pedro’s band meets them at the Roxy and the battle begins. Backstage, the Man becomes ill from some drugs that Jade gave him, and vomits in the women’s bathroom. Across the street, Stedenko and his squad stake out The Roxy and decide to dress up as Hare Krishna missionaries to talk their way inside. When the plan doesn’t work, Stedenko spots the fiber weed van just as someone tries to tow it. Inside, Pedro and the Man take to the stage, but the Man is still sick and falls off of his drum stool. Outside, a bystander throws a lit cigarette at the van, and it catches fire. The marijuana smoke intoxicates Stedenko and the squad as it floats into The Roxy. Perked up by the marijuana cloud, the Man plays energetically with Pedro’s band and they perform to an enthusiastic crowd. The next day, Pedro excitedly talks about the band’s future as he and the Man drive down the highway. Hardly paying attention, the Man pulls out another joint to smoke.