Accountants Larry Wilson and Richard Parker discover the source of a $2 million discrepancy—multiple payouts made against the same life insurance policy. They agree to tell their boss, Bernie Lomax, on Monday morning. When they arrive at work Monday, they see Gwen Saunders, a summer intern on whom Richard has a crush. Larry urges his colleague to ask Gwen out on a date before she returns to college, but Richard is too shy, and gets tongue-tied, and can only tell the bemused Gwen that his aunt is ill when Larry pushes him into talking to her. Bernie Lomax shoos the two young men out of his office before they can tell him about the multiple payments, and tells them to come back after lunch. As Larry and Richard eat lunch at a sidewalk hotdog cart, they see the well-dressed Lomax and a beautiful blonde get out of a Porsche sports car and enter an expensive restaurant. Back at the office, Gwen runs into Richard and Larry coming out of the elevator as she is about to get in. Larry shoves Richard back into the elevator with Gwen. A short time latter, at Larry’s desk, Richard boasts that he has made a dinner date with Gwen. When they finally see their boss and tell him of the fraud, Lomax asks Richard and Larry to call him Bernie, suggests they keep quiet until he can check their figures, and invites them to his beach house for Labor Day Weekend. Larry and Richard are elated, thinking that Bernie loves them. However, when Bernie joins Vito, a mafia boss, for dinner, he asks the mobster to have the two young men killed, suggesting it could be made to look like a murder-suicide. Vito seems to go along, but when Bernie leaves, Vito tells his associate, Paulie, to kill Bernie, instead, because he is getting careless and having an affair with his girl friend, Tina. Outside, the restaurant, Tina, insists on seeing Bernie over the weekend, and he tells her to come to his beach house Friday night. After their date, Gwen tells Richard she is sorry he did not ask her out sooner, because this was her last day at the office before returning to college—and she is unable to spend the weekend because she is going out of town to be with her parents. When they want to go someplace quiet to talk, Gwen suggests they go to Richard’s apartment. Too embarrassed to tell her he lives with his parents, Richard takes Gwen home hoping they will be asleep. As Gwen and Richard start to kiss, Richard’s father comes to the kitchen in his underwear to get a drink. Richard tries to pass “Monroe” off as his butler, but Gwen is unimpressed and bids him good-bye. Friday, Bernie arrives on Hampton Island by speedboat, followed by Paulie, who comes by ferry. Paulie calls Bernie from the dock to get his address, and Bernie picks up his phone as the answering machine kicks in. As Richard and Larry make their way to the island on a later ferry, Paulie injects Bernie with a fatal dose of drugs, and leaves a baggie filled with the drug behind to suggest Bernie accidentally overdosed. Paulie then disguises himself as a clergyman and returns to the mainland by ferry, bumping into Richard and Larry as they get off. Arriving at Bernie’s house, they find their host dead, and discover the planted drugs. Fearful the police might think they were involved, Larry and Richard panic—and their panic increases when denizens of the island come in to party. Although Larry and Richard try to tell the newcomers Bernie is dead, they merely think their host is drunk, and talk to the corpse as if Bernie was still alive. When Richard attempts to call the police, Larry tells him it would be “disrespectful” to deny Bernie’s last wish to show them a good time, and suggests they pretend Bernie is still alive—at least for a little while. Richard will have none of Larry’s plan until he sees Gwen out on the porch coming to the party. Richard patches things up with Gwen and promises to never lie again, but when Gwen spots Bernie and wants to thank him for her summer job, Richard and Larry rush to “walk” the corpse out of the house as Gwen is waylaid by drunken guests. By accident they dump Bernie’s body off the balcony onto the beach below. Richard spots Gwen by the water. She tells him she does not like most of the people at the party, and invites him to come with her to a lighthouse where they can get a good view of the island. As Bernie’s body lies on the sand, the tide begins to come in. At the top of the lighthouse, Richard inadvertently stares at the high intensity light as it sweeps around and becomes temporarily blinded. Unable to see the trap door to the stairs, he stumbles and falls down several flights. Back on the beach with Gwen, limping and in pain, Richard makes light of his injuries, but as he and Gwen lie on the beach kissing, Bernie’s body washes up beside them. Richard distracts Gwen’s attention before she sees the body, and hustles her away. Richard then enlists Larry to help drag Bernie’s body back to the house. However, Vito’s girlfriend, Tina, shows up drunk looking for Bernie. Pulling a knife, and demanding to know where he is, the young men tell her Bernie is in bed upstairs. Outside the house, one of Vito’s thugs observes Tina enter Bernie’s bedroom. A half hour later, not wanting to be implicated in Bernie’s death, Tina comes back downstairs and tells Richard and Larry she had a wonderful time with Bernie, then leaves to return to the mainland. The thug reports to Vito by telephone that Bernie cannot be dead, because Tina just spent time in bed with him. The next morning, Larry props Bernie on a patio chair and rigs his arm with string so he can make Bernie wave when visitors stroll by and say hello. Paulie returns to the island to clean up loose ends. Gwen arrives at the house to have her delayed conversation with Bernie, but Richard finally informs her that Bernie is dead. In light of his past lies, however, she does not believe him. As they talk, Larry dumps Bernie’s body off the porch, and it lands on a startled Paulie, who believes Bernie is attacking him. He strangles the corpse and “kills” Bernie yet again. Upset with Richard, Gwen leaves. As he tries to call the police, Richard activates Bernie’s answering machine and plays back the conversation in which Bernie told Paulie to kill the young men after he is off the island and has an alibi. They discover a briefcase filled with money, and the murder-suicide note Bernie wrote, purporting to be Larry, claiming Richard and Larry stole the money to pay for Larry’s sex change operation, but that Richard has put an end to their relationship and Larry cannot live without his former lover. Richard and Larry decide they are in danger, but when they remember Bernie did not want them killed while he was on the island, they decide to “revive” Bernie so would-be killers will think he is still alive. They look over the patio banister and see a young boy burying Bernie in the sand. They chase the boy away, and as they vacuum the sand off Bernie back in the house, they hear gunfire, and hide. It turns out to be the boy exacting revenge with his cap gun. Larry and Richard hustle Bernie’s body back to the ferryboat and attempt to “walk” Bernie toward the ferry, as it leaves the dock. Paulie sees the man he killed twice seemingly very much alive. The young men return to the house with Bernie to get his speedboat key, but two tradesmen arrive. Taking the men for killers, Richard knocks them out and shoves them in a closet. Richard and Larry finally get to Bernie’s speedboat, but forget to cast off when they pull away. In the ensuing confusion they crash into several other boats dragging Bernie behind them at the end of a rope, before finally running out of gas in the open sea. Larry and Richard paddle back to the island with Bernie’s body, even as Paulie hires a boat to return and kill Bernie yet again. Gwen sees Larry, Richard and Bernie return and confronts Richard for lying about Bernie being dead. Larry Drags Bernie’s body out, tells her they are in danger, and asks if they can stay at her house. Gwen becomes terrified, but just then the tradesmen burst out of the closet. Richard knocks them out again, but Paulie shows up and pumps several bullets into Bernie’s corpse. Realizing there are witnesses, Paulie attempts to shoot Larry, Richard and Gwen, but discovers his handgun is out of ammunition. Paulie has a second gun, however, and chases after the three. As Richard and Gwen go to call the police, Larry stays behind and, in a struggle, manages to tie up Paulie with a telephone cord and knock him out. After the police wrap up the scene and the coroner is about to take Bernie’s body away, the ambulance bumps into the loading ramp, sending the gurney with Bernie’s body careening down a ramp. When it hits the sand, Bernie’s body tumbles and lands on the beach behind Richard, Gwen and Larry who are sitting on the sand. When a neighbor hollers, “Hi, Bernie,” and waves, they realize the corpse is still with them and run off. The little boy comes up with his sand pail and asks if he can bury Bernie again. The body falls over, and the boy takes this for a “yes,” and pours sand over the body.