A prostitute sets out to frame a cop.

In New York City, vice squad detective Sgt. Whitey Brandon and his partner Ben Dunton intercept hoodlum Mugsie who has arrived in town escorting a young woman from out of state. Suspecting Mugsie of working for racketeer Vince Malone, Brandon threatens him with arrest, frightening the hoodlum into agreeing to inform in exchange for immunity. Unknown to Brandon, Dunton is on Malone's payroll and while Brandon escorts the underage girl to purchase a return ticket, Dunton encourages Mugsie to escape, then shoots him in the back. Later, Brandon and Dunton report to vice squad head Capt. William Brennan, who expresses frustration that all their leads to Malone's prostitution ring end in failure. Brandon reveals his discovery that Malone is using modeling agencies as fronts for his call girl service and recommends an undercover investigation. Meanwhile, at Malone's offices, after learning of Mugsie's death, Malone complains about the incorruptible Brandon and arranges with his second-in-command, Phil Evans, to set a trap to discredit the detective. Malone hires beautiful Carol Hudson from the Detroit branch of the syndicate to work in one of his fronts, the Star Modeling Agency. Soon after, Brandon begins investigating several modeling agencies in the guise of a photographer and visits Star Agency. As planned, Carol receives the assignment and meets Brandon at a hotel for the photo session. Carol soon maneuvers Brandon into paying her to stay the entire evening, after which Brandon arrests her. A few days later, Brennan summons Brandon to inform him that Carol's lawyer has accused Brandon of extortion and entrapment, which will require an investigation. At the subsequent hearing, Carol testifies that Brandon demanded a hundred dollars for not turning her in. Having expected this, Brandon is completely surprised when Dunton then swears that his partner has a long history of crooked dealings. Found guilty of accepting payoffs, Brandon is suspended. Furious, Brandon confronts Dunton later and his partner admits that his need for money to support his family drove him to accept a deal with Malone. Pleased with Carol's performance and captivated by her looks and style, Malone asks her to stay under personal contract and Carol agrees. After moving into a lavish, penthouse apartment provided by Malone, Carol is surprised when her younger sister Louise unexpectedly arrives for a visit. Having long admired Carol's modeling career, Louise pleads to stay and learn about the business. The sisters are startled when Brandon calls on Carol and accuses her of being in cahoots with Malone, then threatens her. Frightened, Carol reports Brandon's threat to Malone the next day and he promises to take care of him. Meanwhile, Evans stops by Carol's apartment and, upon discovering Louise trying on one of Carol's expensive dresses, tells Louise he is a business associate of her sister's. Picked up by Malone's henchmen, Brandon is taken to meet the crime boss and, blaming Malone for the loss of his job, demands to be let in on Malone's racket. Malone scoffs at Brandon, who confidently vows to ruin him. Later that night, Malone's men beat Brandon up, prompting the concerned Brennan to visit him. Brandon explains his plan to build a counter modeling business to damage Malone's reputation with the syndicate and the captain agrees to help. Over the next several days, Brandon sets up numerous modeling agencies, then offers Carol a position, which she angrily rejects. Brandon then arranges with Brennan to raid several of Malone's agencies, including Star, and has Carol held in police custody. The ploy works and Malone is angered by Brandon's display of strength. After Carol is released from jail upon Brandon's orders, Evans drives her home and confides his certainty that unless Malone resists Brandon's takeover attempt, he will soon be exiled by the syndicate. Implying it would be beneficial for Carol to accept his advances, Evans is outraged when Carol slaps him and refuses. A few nights later, Brandon returns to his apartment to find a drunken Dunton, who admits that Malone sent him to kill his former partner. When Dunton proves too ashamed to carry out the job, Brandon convinces him to confess to Brennan and Dunton agrees with relief. Just outside Brandon's apartment, however, Malone's men lie in wait and, seeing Dunton emerge alone, shoot him. Angered over Carol's hostility toward him, Evans telephones Louise one afternoon and, suggesting that a modeling job is possible, invites her to his apartment. When Louise arrives, Evans reveals his involvement with Malone, but when he describes Carol's relationship with the mobster, Louise is shocked and refuses to believe him. Later that evening, Carol is summoned to the hospital and learns that Louise has been beaten and raped by Evans in anger over Carol's earlier rejection. Outside the hospital, Carol runs into Brandon who expresses his sympathy over Louise's attack and suggests that if Carol helps him apprehend Malone, Evans would also be arrested. Carol declines, however, declaring she has nothing against Malone. Back at her apartment, Carol finds Malone, but is dismayed by his indifference to Louise's assault and refusal to castigate Evans. Angered, Carol later telephones Brandon and agrees to help him get Malone. Over the next few days, Carol provides Brandon a detailed list of Malone's modeling agency fronts which Brennan then raids, arresting the employees on morals charges. Alarmed by the disruption of Malone's territory, three syndicate bosses travel to New York to meet with him. When Brandon receives an invitation to join the meeting, he asks Carol to accompany Malone and carry a tape recorder. Having learned from Brennan that Evans has been arrested attempting to flee town, Carol agrees and carries the recorder in her purse to the meeting. Impressed by Brandon's power, the syndicate bosses ask him to replace Malone, but before he can respond, Malone inadvertently finds the recorder. A fight breaks out between Malone and Brandon and the bosses attempt to escape, only to run into Brennan's men, who capture Malone fleeing with the recorder. Several days later Brandon, restored to the police force, escorts Carol and Louise to the bus station as they return home to start a new life.