A retired gangster has to pull off a hit when his daughter is kidnapped.

Former mobster Tony Banks now operates a carwash and lives with his wife, Flo, in an affluent San Francisco suburb. His peaceful existence is disrupted, however, when his teenaged daughter, Darlene, falls in love with Stash, a long-haired hippie, and two underworld cronies, Hechy and his son Angie, arrive with word that their gangland boss--"God"--wants Tony to do one last job by rubbing out "Blue Chips" Packard, an imprisoned mobster who is planning to tell all to a Senate crime committee in return for a life of luxurious solitary confinement. At first Tony balks at "God"'s suggestion, but he changes his mind when his best friend, Harry, is shot through the head. Once Tony's imprisonment has been arranged, Flo permits Stash and his flower friends to camp on the front lawn and take over the household. While in jail Tony ingests some LSD-soaked stationery belonging to his draft-dodging cellmate, the "professor," and goes on an acid trip that convinces him that violence is evil. To avoid killing "Blue Chips," Tony and the professor get the entire prison high on LSD-spiked soup and then make a getaway in garbage cans attached to balloons made from plastic food bags. As they make an aerial landing on "God"'s yacht, where Darlene is being held prisoner, Flo and Stash arrive by water with a flotilla of hippies. Outwitted and outnumbered, "God" (dressed in hippie clothes) sails off on a raft with the professor, and Tony is happily reunited with Flo, Darlene, and Stash--his new son-in-law.