Cisko is an ex-rockstar who has become a drug addict. A corrupt cop blackmails Cisco to sell marijuana for him. Cisco has one weekend to sell it to his friends.

Following his arrest for selling marijuana, Cisco Pike, a fading rock star who, in the space of four years, has gone from winning gold records to pawning his guitar, vows to give up dealing and try to reestablish himself in the music business. One day, Leo Holland, the narcotics officer who arrested him, knocks on the door of the seedy, beachfront apartment Cisco shares with his girl friend Sue, and coerces him into taking a ride. Holland drives Cisco to a padlocked garage to show him one hundred kilos of high-grade marijuana that he has stolen. Thinking that Holland is trying to entrap him, Cisco asks his lawyer to check out the address of the garage, and upon learning that it is attached to Holland's house, agrees to meet the officer at the beach on Friday afternoon. There, after explaining that he needs $10,000 by Monday morning, Holland asks Cisco to sell the marijuana, offering in return to help get the drug charges against him dropped and let him keep any cash he raises beyond the $10,000. When Cisco queries why he needs the money, Holland replies that he has a margin call coming due on some stocks and had borrowed against his life insurance to pay for it. Later, upon finding Cisco cutting up bricks of marijuana in their kitchen, Sue becomes upset because Cisco had promised to stop dealing, but he reassures her that the marijuana is for their own personal use. Trying to unload the marijuana, Cisco begins calling his old contacts, but when he spots Holland following him, he declares that he is quitting. Later, Holland, visibly jittery, comes to Cisco's apartment and threatens to kill Cisco unless he delivers the $10,000 on Monday, then chides him for smoking cigarettes because it is bad for his health. After meeting his dealer friend Buffalo, who promises to help him market the marijuana, Cisco proceeds to a studio where his musician friend Rex is recording a new record. Cisco has given Rex a tape of some new songs he has written, but when Rex returns the tape and expresses disappointment in the music, Cisco offers to sell him some marijuana instead. At the studio Cisco meets Merna, a pregnant, rich, eccentric hippie who lives with her father at his mansion. After asking to buy some marijuana, Merna invites Cisco home with her and along the way, they pick up Merna's younger girl friend Lynn. Returning home after having sex with Merna and Lynn, Cisco is confronted by Sue, who has discovered that he is dealing drugs again and angrily threatens to leave him unless he stops. Cisco then goes to sell thirty kilos, but when the buyer informs Cisco that he will pay him after he in turn has sold the drugs, Cisco insists on riding along with him to meet his contact. Upon meeting the buyer at a parking lot, Cisco, sensing a set-up, jumps back into the truck and speeds off with the dealer. Hearing the sound of sirens in the distance, Cisco ditches the truck and hops onto a city bus with the dealer. When Sue picks them up, she angrily questions Cisco, but he refuses to respond. Upon returning home that night, Cisco and Sue find Jesse Dupre, his partner in his former rock band, sitting in his bathtub, strung out on speed. Cisco, who was hoping to put their act back together, listens as Jesse incoherently rambles on about leaving his wife and realizes that his former partner is no longer able to function as a musician. After finally telling Sue about his predicament, Cisco leaves with Jesse to meet Buffalo at a music club in which they used to perform. Although Buffalo fails to keep the appointment, Cisco sees Merna and Lynn there and introduces them to Jesse. When Merna suggests that her rich neighbor Jack might be interested in buying ten kilos from Cisco, they drive to Jack's house, where with Merna's help, Cisco consummates the deal. Meanwhile, Holland comes to the apartment looking for Cisco. Frightened by his agitated, sweaty demeanor, Sue sneaks out the back door. To celebrate the sale, Merna invites them all back to her house, where she offers Jesse some heroin. Jesse secludes himself in the bathroom to inject the drug, and when the others hear a crash, Cisco rushes in and finds his friend dead from an overdose. Driving Jesse's body back to the beach, Cisco finds Sue waiting in the parking lot to warn him about Holland. After the two carry Jesse's body to a bench on the beach, Sue, reasoning that if she phones the police an ambulance will be sent to pick up the body, goes to a pay phone. Although Sue is afraid of Holland, Cisco insists upon returning to the apartment to pay him. Once Cisco hands over the $10,000, Holland admits that he lied about needing the money for stock and explains that he has a heart condition that will cause his dismissal from the force, rationalizing that because he has not served enough time to earn a pension, the force owes him the money. When the ambulance and police arrive to pick up Jesse's body, Holland thinks that Cisco has double-crossed him and begins to fire his gun at him. As Holland chases Cisco onto the beach, a police helicopter shines its searchlight on Holland, affording the officers a clear shot. Not realizing that Holland is a fellow officer, the police gun him down. Soon after, as Sue returns to her apartment, Cisco drives along the highway, heading out of Los Angeles.