Grimm rides a New York City subway dressed as a circus clown in full makeup. He arrives at a bank at closing time, points a gun in the guard’s face, and opens the front of his costume to show that he is wired with dynamite. When he announces he is robbing the bank, none of the customers or tellers take him seriously until he fires his gun in the air. The bank manager, Princeton, presses a silent alarm button. Grimm orders a teller to fill up a bag with money, and to give a customer his receipt so that he can prove he deposited money into his account. He herds everyone into the vault and shoots the bank’s security cameras, as police arrive outside and set up barricades. New York Police Department Chief Dennis Rotzinger telephones Grimm to negotiate. Grimm identifies himself as “Chip,” and demands that a city bus, a Harley-Davidson motorcycle, a “monster” truck, and two helicopters be delivered in thirty minutes. He agrees to release one hostage for every demand that Rotzinger meets. In the vault, hostages turn their anger on Loomis, an hysterical young man who weeps because he thinks they are going to die. When Grimm informs them he is going to trade a hostage, a “yuppie” in a business suit elects himself to be the first, but Grimm lets the hostages vote. They all point to Loomis, the crybaby, and Grimm sends him out. When Grimm ogles Phyllis, a statuesque blonde hostage, she belittles him in a torrent of insults. Frightened that Phyllis’s contempt might inspire the clown to blow them up, Princeton suggests that Grimm release her in return for the next demand. Police deliver a bus and a motorcycle, and Grimm releases Phyllis from the vault and, out of sight of the hostages, changes into another disguise as a redheaded man. He and Phyllis run out the door into the arms of the police and tell Chief Rotzinger that the robber is acting crazy and has placed dynamite throughout the building. When a monster truck arrives, the chief telephones Chip, but no one answers. He decides to storm the bank at five o’clock if the robber does not call back or release another hostage. At five o’clock, Grimm telephones Chief Rotzinger from a booth in Brooklyn and asks for more time. Now, without their wigs, Grimm and Phyllis are joined by the crying hostage, Loomis, who is actually Grimm’s boyhood friend and also in on the robbery. Hoping to stall for time, Grimm telephones the chief to complain that the monster truck does not have a “hydraulic-lift body,” but Loomis, sitting in the nearby getaway car, honks the horn. After analyzing a tape of the conversation to make sure the sound is not a clown horn, Chief Rotzinger orders his men to break into the bank and free the hostages. Meanwhile, Phyllis has something to tell Grimm, but she is continuously interrupted. Loomis becomes lost in the slums of Brooklyn because street workers have temporarily moved signs pointing to the Brooklyn-Queens Expressway. When they ask a man on the street for directions, he pulls a gun, steals Grimm’s wallet, and drives away. They return to Phyllis’s apartment and change their clothing, taping their $1 million loot to their bodies. Suddenly, a fire engine arrives outside to douse a fire across the street, but Loomis’s car blocks the hydrant. Just then, Hal Edison, who is about to move into the soon-to-be-vacated apartment, enters and pulls a gun on the group, believing they are there to rob him. By the time Grimm convinces him otherwise, the firemen have pushed Loomis’s car out of the way, and it rolls down the hilly street, crashing into a park. Meanwhile, as Chief Rotzinger gathers the hostages, he realizes that the three captives released were actually the criminals. Rushing to the airport, Grimm announces that he made a back-up airline reservation for an eleven p.m. flight to Martinque when the three crooks miss their scheduled flight out of town. Phyllis argues with Grimm, accusing him of being a liar, as well as being a bank robber. He reminds her that they planned the robbery in her bedroom. They flag down a taxicab, but the Arabic driver does not speak English, and repeatedly runs red lights. Loomis becomes hysterical, jumps out of the moving taxi to catch another one, and slams into a kiosk, knocking himself out. When Rotzinger hears a police report about two men and a woman who jumped from a taxicab, he sends police units to the scene. As sirens approach, Loomis revives and Grimm and Phyllis help him to his feet and hurry away. They stumble into a warehouse where several gangsters are counting money. Grimm talks quickly and, utilizing the information he gleans from the gangsters’ comments, convinces them he is the man they have been expecting, Vince Lombino’s bagman. The boss, Mike Skelton, gives Grimm a bag containing $6,000. Grimm, Phyllis, and Loomis hurry to catch a passing bus, but the driver demands exact change. When Grimm returns from a convenience store with the exact bus fare, both the real bagman, Mario Minetti, and the Arabic taxi driver see him and give chase. Grimm climbs on the bus as several police officers stop Minetti, recognizing him as a member of the Lombino mob. In the confusion, the police believe Minetti was one of the bank robbers. En route to John F. Kennedy [JFK] International Airport, Phyllis confides to Loomis that she has been trying to tell Grimm she is pregnant. However, now that she has seen him “con” the police, the mob, and the gun-toting renter, she fears he will be unable to live a “normal” existence. At police headquarters, Rotzinger interrogates Minetti and asks if the clown works for Lombino, and orders an interpreter for the Arabic cabbie. Finally, the chief learns that Minetti was chasing Grimm onto the bus before police arrested him. Meanwhile, Grimm gives the mob’s six thousand dollars to an annoying, drugged-up passenger in return for him getting off the bus. At the nearest stop to the airport, the three criminals get off the bus and find themselves in a desolate barrio. Phyllis finally tells Grimm she is pregnant as an airplane flies overhead. They sneak into a JFK baggage cart to enter the airport. Elsewhere, Minetti shares that Lombino is catching an eleven o’clock flight to Martinique, and Rotzinger, believing the mob boss masterminded the robbery, alerts the head of airport police. Grimm, Phyllis, and Loomis pay the baggage cart driver $1,200, and Grimm hurries to the check-in counter where Vince Lombino and his wife are also checking in, under the pseudonyms, “Russ” and “Mrs. Crane.” Phyllis again complains about Grimm’s behavior and insists on staying in New York City. Grimm orders her to meet him on the airplane in two minutes, and pushes Loomis in a wheelchair toward a bathroom, where they remove the money and put it in a bag. Loomis advises Grimm that he should have told Phyllis he loved her. When they board the airplane, Phyllis’s assigned seat is empty, and Grimm decides to get off and search for her. However, Rotzinger steps forward with his gun drawn, but instead of nabbing Loomis and Grimm, he arrests Vince Lombino. When the gangster puts up a fight, Grimm helps Rotzinger subdue him. Phyllis steps out of the airplane bathroom, and the metal door hits Lombino on the head, dazing him. Rotzinger and his officers escort the mobster off the plane. Rotzinger thanks Grimm for his help and wants to award him a formal commendation. Grimm identifies himself as “Jan Chipowski.” Reporters hail Rotzinger for capturing the mobster, but when he mentions to his assistant that they need to thank Jan Chipowski, the chief recalls that the bank robber’s name was Chip. On the airplane, Loomis sleeps while Grimm and Phyllis kiss.