Hitman Trabucco has successfully eliminated two witnesses against the mob; He now has to kill Rudy “Disco” Gambola before his grand jury testimony against his fellow mobsters, but completing the contract becomes difficult once Trabucco encounters Victor Clooney, an emotionally disturbed, suicidal television censor who unintentionally causes a variety of annoying problems for the hitman. Victor is hoping to reconcile with his estranged wife. Trabucco takes a room in the Ramona Hotel in Riverside, California, which is located directly across the street from the courthouse where Gambola is to testify. Trabucco plans on killing Gambola using a sniper rifle.
Victor has a room connected to Trabucco’s room at the hotel. He tries unsuccessfully to hang himself; then Victor climbs onto the ledge outside his window. Trabucco is afraid of the attention from the police stationed around the courthouse, so he agrees to drive Victor to the Institute for Sexual Fulfillment, the nearby clinic where Victor’s wife Celia, a researcher for 60 Minutes, is gathering information for a segment on the program. Trabucco tries to kill the irritating Victor, but is unintentionally thwarted during each attempt. At the clinic, Victor discovers Celia is having an affair with the clinic’s director Dr. Zuckerbrot, who is worried her husband’s suicide will reflect badly on his practice. Celia and Zuckerbrot go to the hotel where the doctor mistakenly injects Trabucco with a tranquilizer intended for Victor. Victor, who until this point was oblivious to the fact Trabucco is a hitman, volunteers to fulfill Trabucco’s contract when the hitman is impaired from the sedative; he feels his life is ruined and has nothing to lose. After overcoming assorted complications, Victor succeeds in shooting Gambola. However, despite Victor’s hopes, Trabucco has no intention of sticking together and parts ways with him following their escape.
Trabucco retires to a tropical island, where months later he unexpectedly is joined by Victor, who arrives thirsty and exhausted and in a dinghy. Victor explains he is wanted by police after blowing up Zuckerbrot’s clinic and Celia ran off with the doctor’s female receptionist to become a lesbian couple. Not especially pleased to see the irritating Victor again, Trabucco suggests to his native servant the possibility of reviving the old custom of sacrificing humans in the local volcano.