Supermodel Vicki Lynn, whose face is seen everywhere, is murdered, and ace homicide cop Ed Cornell cuts his vacation short to take the case personally. In flashback we see how Vicki rose from ambitious waitress to big black headlines, courtesy of clever publicity man Steve Christopher. Now Cornell seems determined to get Christopher convicted in what begins to seem like a bizarre personal vendetta. Is Steve caught like a rat in a trap?

After the slaying of New York glamour girl Vicki Lynn, zealous homicide detective Ed Cornell insists on canceling his vacation and heading the investigation. Upon his arrival at police headquarters, Cornell learns that Steve Christopher, the promoter responsible for Vicki's career, and Jill Lynn, Vicki's sister, are being questioned. Cornell grills the exhausted Christopher, who relates how he met Vicki: Several months before, Christopher and influential columnist Larry Evans are returning from the opening night of a new play starring their friend, Robin Ray. Seeing the pretty Vicki through the window of the cafeteria in which she works, Christopher and Evans enter and tell Vicki that Christopher, a successful publicity man, could package her, like any product, and give her a better life. Vicki comes to Christopher's office the following day, and after outfitting her in an expensive gown, he takes her to a prominent nightclub, where she has her picture taken with Ray. Christopher assures Vicki that with his help, she can become New York's top model, and Vicki, fueled by ambition, vows to work hard. Back at the police station, Jill tells Capt. J. Donald, the head of homicide, that she was surprised by Vicki's demeanor after she returned home from her nightclub outing, and was uneasy about Vicki's ambitions, but nonetheless supported her. Jill relates that the next morning, when Christopher came to pick up Vicki, she questioned his motives, but he assured her that his relationship with Vicki was strictly business, and showed her a prominent mention of Vicki in Evans' column. During the next few months, Vicki's fame grew, and Jill relates that all was going well until two nights earlier: At the club, Jill tensely awaits the arrival of Christopher, as she knows that Vicki has bad news for him. Vicki tells Christopher and Evans that she has made a successful motion picture screen test and will be leaving the following day for Hollywood. Christopher is angered by Vicki's cavalier attitude toward his hard work on her behalf, and Jill is irritated by Vicki's accusation that she is in love with Christopher. Back in Donald's office, the chief asks Vicki if any men had bothered Vicki, and Jill remembers that one mysterious man would hang around the cafeteria, staring intently at Vicki. Jill is horrified when Cornell enters the room and she recognizes him as the man she described, but he dismisses her concerns and commands her to tell him about the car ride she insisted that she, Vicki and Christopher take after Vicki broke the news about her movie contract: During the drive, Vicki tries to reconcile with Christopher, asking him to take her to the airport the following day, and again asserting that he and Jill will be glad to get rid of her because they are in love. Cornell wonders what Vicki meant by "getting rid of her," then learns from Jill that Christopher was already in the apartment when she discovered Vicki's body. Cornell insists that Christopher is the killer, but he and Jill are released because Harry Williams, the switchboard operator at Jill and Vicki's building, is missing and is presumed to be the killer. That night, as Christopher tosses and turns, unable to sleep, he finds Cornell sitting in his bedroom, and the cold-hearted detective assures Christopher that he will see him electrocuted for the crime. The next day, with Harry's alibi of visiting his parents confirmed, Donald orders Cornell to question Ray and Christopher. When Cornell shows them Vicki's screen test, Ray becomes hysterical, and although he confesses that Vicki laughed at him for falling in love with her, Cornell dismisses him after verifying his alibi. Meanwhile, as Jill moves into a new apartment, she discovers a note from Christopher to Vicki, stating that the sooner Vicki is "out of the way," the better. Unsure about Christopher's meaning, Jill asks him to meet her, and after spending the evening together, decides that he is incapable of murder. Returning to her apartment, Jill gives Christopher the inflammatory note, but Cornell, who is hiding in the closet, grabs the note and handcuffs Christopher. Cornell taunts Christopher and threatens to beat him, until, panicked, Jill knocks Cornell unconscious from behind. Helping Christopher to the roof, Jill admits that she loves him, and the couple embraces. Christopher then asks Jill to meet him at a repair shop to remove the handcuffs, but when she arrives, she is arrested. Hoping that Jill will lead him to Christopher, Cornell has her released. At home, Jill finds cards taken from flowers at Vicki's grave, all of which read "Until tomorrow--because I promised." Jill then goes to an all-night movie theater, which Christopher had earlier mentioned, and shows him the cards. Christopher recognizes the phrase as one which Evans uses to sign off his column, and goes to question him. At Evans' apartment, Evans admits he has been sending the flowers to Vicki's grave because he had promised to send her bouquets in Hollywood. He then reveals that just before Vicki was killed, he escorted her to her apartment, and tried to get the passkey from Harry, as Vicki had forgotten her key, but Harry was not at the desk. Evans climbed up the fire escape and upon entering Vicki's apartment, smelled cigarette smoke but dismissed it. Realizing that Harry must have murdered Vicki, Christopher enlists police sergeant McDonald and Jill to help trap him, and soon after, the addled Harry, who secretly loved Vicki, confesses. Harry also reveals that Cornell was aware of his guilt but let him go. Enraged that Cornell tried to frame him, Christopher goes to the detective's apartment, where he is astonished to find a shrine of candles and flowers in front of photographs of Vicki. Cornell reveals that he was desperately in love with Vicki and blames Christopher for taking her away from him through his promotion schemes. Christopher tells Cornell that Vicki had no interest in him, and Cornell, in despair, begs Christopher to shoot him. Christopher cannot do it, however, and Mac arrests the crestfallen detective. In the daylight, Christopher and Jill kiss and hold hands as they walk along the street, impervious to the fact that Vicki's posters are being covered with those of a new glamour girl.