Late one night, Melsa Manton, a young heiress and leader of the "Park Avenue Pranksters," sees Ronnie Belden fleeing from George and Sheila Lane's house and, investigating, finds a diamond brooch and a corpse inside. Terrified, she runs to telephone the police, but when they inspect the house, the body and brooch are gone. Convinced that Melsa is playing a trick, Lieutenant Mike Brent dismisses her declarations, and the next day, Melsa reads a scathing editorial about the incident in the Morning Clarion . After threatening the author, editor Peter Ames, with a libel suit, Melsa calls the other six pranksters together to locate the missing corpse. While scouring the Lane house, the girls stumble across Peter and promptly gag and tie him, and then move on to Ronnie's apartment, where they find the brooch and Ronnie's body in the refrigerator. After the pranksters deposit the new corpse at the Clarion , Brent drills a scornful Melsa about Ronnie. Grateful for Peter's unexpected help in locating her lawyer, Melsa reveals to him that she has the brooch. As they are leaving the station, however, Brent apprehends Melsa and the jewel, just as the police discover George Lane's body in Ronnie's car. Now suspecting the absent Sheila Lane, who was having an affair with Ronnie, Peter, the police and the pranksters descend on a charity ball that is co-sponsored by the widow. Melsa, overhearing Peter and Brent discussing Lane's life insurance policy, takes prankster Helen and sneaks over to Lane's brokerage firm, where they are met by Peter and a professional safecracker. In the company safe, they find incriminating papers about Sheila's first husband, criminal Eddie Norris, who then shows up with a gun. After Peter overwhelms Eddie, Melsa, who believes Eddie is innocent, conducts travel time tests to prove his murder alibi to the police. However, when Melsa receives threatening phone calls and Peter is shot at from a passing car, the police decide to use Melsa as a decoy. In the end, Melsa determines that Eddie actually was the killer and is saved from his bullets by Peter, who has finally won her stubborn heart.