In a high-school game of Killer (in which a student must shoot another with a squirt gun) Matt Arnold has to "shoot" classmate Jenny Herk, and decides to sneak up on her at home. By coincidence hitmen are also there to kill Arthur Herk, who has secretly embezzled money from his company. When the fake assassination attempt crosses paths with the real one, police officers Monica and Walter are called out to the resulting disturbance. Eliot Arnold, Matt's father, who was contacted by Matt's friend, Andrew, immediately feels a mutual attraction to Anne Herk (Jenny's mother), as Matt and Jenny begin to feel attracted to each other as well. The Herks' Mexican housemaid Nina, meanwhile, falls in love with a young man named Puggy, who lives in a tree on their property, after she runs from the shootings and he saves her from the hitmen.
Realizing that he is the intended victim, Arthur visits arms dealers, for a weapon, but ends up with suitcase nuclear bomb. Escaped convicts Snake and Eddie, who were previously kicked out of a bar called the Jolly Jackal for disorderly conduct, hold up the bar and kidnap Arthur and Puggy (who is an employee there) for the suitcase, not knowing its contents.
Meanwhile, Matt tries to "kill" Jenny in a mall parking lot, but a security guard thinks that Matt's gun is real. After the guard opens fire on them, Matt and Jenny run to the Herk house, followed by Monica and Walter, who stumble across the confusion. Eliot is called over as well.
The convicts force Arthur to return to his home, where they capture everyone and tie them up. Taking Puggy and kidnapping Jenny, they leave (with the suitcase) for the Airport. Nina, who was hiding in her room, frees everyone except for Monica and Arthur (who were handcuffed to a heavy brass etagere). Shortly after, the house is visited by two FBI agents who are tracking the bomb. They free Monica and have her lead them to the airport (leaving Arthur, as he was poisoned by a hallucinogenic toad, causing him to think that his dog is possessed by Martha Stewart).
The criminals reach the plane still holding Jenny hostage. Puggy manages to escape, but the bomb is enabled when going through security; as a condition of them being let through. They made security believe it was a garbage disposal. The FBI agents tell everyone that unless the bomb is retrieved soon, the plane must be shot down. They find Puggy who leads the group to the criminals' plane, which Eliot sneaks onto.
Meanwhile, the two hitmen get out of the traffic jam (caused by Snake and Eddie) and reach the airport. They bump into Officer Romero, and Special Agents Greer and Seitz, knocking the hitmen's Remington Sniper Rifle out of their golf bag in the process. The FBI agents, having more serious problems, leave this to Romero since it's her "jurisdiction." Romero grabs the rifle, and removes its bolt, rendering it useless. She then tosses the rifle down, saying: "gentlemen" and leaves. Henry Desalvo remarks to Leonard that Miami sucks...but the cops are kinda nice.
Eliot, having sneaked onto the plane, attacks the criminals by knocking Eddie out with a fire extinguisher and blasting the extinguisher at Snake. After being told the suitcase must be gotten off the plane, Eliot hurls it out of the now open plane door, only for Snake to leap after it. In a memorable feat of dumb luck, Snake manages to cling onto some steps still coupled to the plane. Despite Eliot's persistence in trying to convince Snake to release the suitcase, Snake shoots at him, and is then told by the pilot that the suitcase is a bomb, prompting Eliot to pull an emergency lever, decoupling said stairs. Snake (in a nod to the stubborn as a mule tale) plunges into the ocean with a defiant smile, still clinging to the bomb, which explodes safely in the water. Eliot is congratulated by the FBI, promised he will receive presidential cowboy boots and a hat, and told the events that took place will never be acknowledged.
The last scene reveals what happens to the main characters: After chasing down a plane, subduing two criminals, and saving Miami from a nuclear disaster, Eliot finally won Matt's respect. Anne and Eliot get married, a week after Anne gets divorced from Arthur. Walter, after a forced strip search by idiotic ariport guards, becomes a male stripper. The two hitmen manage to get on a plane out of Miami after a series of very weird events. They claim their Miami job was the lowest point in their careers. However, they're surrounded by the fans of Florida Gators on their plane home; which was a constant joke in the film and unfortunately are delayed on the tarmac due to an obstruction on the runway which happened to be the goats that got released during the traffic jam caused previously by Snake and Eddie. Eddie goes back to jail in a prison outside of Jacksonville, but becomes friends with another dimwitted inmate who shares the same affinity for...crude jokes as Eddie does. Arthur is last seen still handcuffed and tormented by his dog.