In the past year, a New York City private detective named Hamberger has accidently shot and killed four people. Although Hamberger was never been indicted for the deaths, his license to carry a gun has been revoked. Because of his involvement in those violent deaths, a Wall Street investment broker named Alex Burton asks Hamberger to kill his wife, Sharon, explaining that she knows too much about his business dealing and could ruin him. Burton offers $25,000 upfront and another $75,000 when the job is done. Hamberger doubts he has the conscience to deliberately murder someone, but nonetheless Burton gives him the keys to his Long Island, New York, home and a copy of his wife’s itinerary. Burton is leaving for Chicago, Illinois, but wants the job done within the week, so that by the time he returns for his company’s New Year’s Eve party, he will be a widower. Hamberger goes to the Long Island home and finds the Burtons' house virtually empty. However, in the refrigerator, he discovers a vial of a drug from Denny Enterprises. A brunette Sharon Burton discovers Hamberger and holds a gun on him, but he is unfazed. He tells her that he was hired to kill her, explaining that if he did not take the job, someone else would. Sharon puts her gun down, starts flirting with him and asks Hamberger to kill her husband instead. She kisses him and the two have sex. Hamberger returns to Manhattan to see his girlfriend, Rina. Soon, police Lieutenant Paul Lefferts comes to Rina’s apartment to report that Mrs. Alex Burton was found dead at her home in the Hamptons and Hamberger’s fingerprints were all over the house, including in the bedroom. Hamberger denies killing Sharon Burton, saying he put her on an airplane before coming back to the city. To avoid arrest, he dashes out the fire escape and goes to Alex Burton’s New Year’s Eve party in a high-rise building overlooking Times Square. Upon seeing Hamberger, Alex Burton grabs a party decoration and attacks him. Hamberger punches him in the face and Burton falls through a window, twenty stories to his death. Party guests report that Alex Burton is stuck in Chicago due to a blizzard. Hamberger asks who just fell out the window, but the guests have no idea who the man was. Lieutenant Lefferts finds Hamberger and arrests him. When Hamberger explains the situation, Lefferts takes him to the morgue. Hamberger says the dead woman is not Sharon Burton, but the medical examiner reports she was positively identified by both her mother and brother. The examiner also says the dead woman had sexual intercourse shortly before her death. When the real Alex Burton arrives at the morgue, Lefferts asks why someone would issue a contract to kill his wife. Burton demands Hamberger be arrested, but Lefferts says they have to follow every lead before making an arrest. An angry assistant district attorney wants the case closed quickly, and gives Lefferts until 10 p.m. on Friday to make an arrest. Hamberger goes to Rina’s apartment and is upset to find a bullet hole in the window. He wants Rina to be careful since she was present when the fake Alex Burton made initial contact with him. Hamberger confronts the doctor who wrote the prescription for the drugs he found in the refrigerator at the Burtons' home. The doctor sends him to the Mallory Agency, a modeling agency, to speak with the owner, Jane Mallory. She says she does not know anything about drugs, but agrees to discuss the matter further over drinks at 4:30 p.m. After Hamberger leaves, Jane Mallory tells her assistant that she will go to the ladies' room at 4:45 p.m. and he should “take care” of the private eye then. Hamberger goes to see a former model named Gloria Reid who is no longer taking the drugs Jane Mallory supplied her. Six months earlier, someone attacked Gloria, cutting her face. She is almost healed, but suggests her attack was connected to Jane Mallory’s drug dealing. Hamberger recommends Gloria find another place to stay for the time being. Over drinks, Hamberger asks Jane Mallory about the drugs. She admits she was supplying Sharon Burton and that when Alex Burton confronted her, the two became friends and ultimately business partners. As she gets up to leave for the ladies' room, Hamberger delays her. A moment later, a helicopter appears outside the waterfront restaurant and begins shooting at the patrons, but no one is hurt. Hamberger and Rina go to Denny Enterprises, located on the fourth floor of Rockefeller Center, to confront the man making the drugs, but find him dead, shot in the head. A man breaks into the office shooting at Hamberger, who gives chase. The man jumps out the window onto the giant Christmas tree in Rockefeller Center Plaza. Hamberger follows and the two have a fight in the tree. They fall onto the ice skating rink below, but the attacker runs away, hopping into a waiting limousine. Confronting Alex Burton at his Wall Street office, Hamberger suggests that because the economy has been doing poorly, Burton has started dealing drugs. Burton denies it, saying the man Hamberger wants is Ambrose Costillion. Hamberger goes to a fashion show to talk to Costillion’s sister, Nancy, one of Jane Mallory’s models. A gunman starts shooting during the show, killing Nancy. Hamberger chases the man, shooting and killing him. Hamberger has Rina take model Gloria Reid to Shea Stadium, where his security guard friend, Carmen, will protect her. Ambrose Costillion and his men search the stadium and capture Gloria. Lieutenant Lefferts attempts to rescue Gloria, but Hamberger shoots Costillion multiple times, killing him. At the Mallory Agency, Jane Mallory is not wearing her blonde wig. When Hamberger sees her natural brown hair, he realizes that she is the person he met at the Burton home in the Hamptons. She explains that Alex Burton fell in love with her and they became partners. Burton wanted to control the heroin drug market, but his wife found out what they were doing. When she refused his money, they concocted a scheme to kill her. Alex Burton comes into the office and holds Hamberger at gunpoint. Jane becomes enraged upon learning that Alex had sex with his wife shortly before her death, and pulls a gun on him. Hamberger and Alex struggle over Alex’s gun. Jane shoots Alex, killing him, then flirts with Hamberger, suggesting they fly to Brazil together. She shoots Hamberger in the chest, but he shoots back, killing her.