A police car moves through the streets of Alhambra, California. The car stops at a police station, and the officers inside it transport their drunk prisoner to the station. Inside the station, Marilyn Gregor (Dolores Fuller) meets Inspector Johns (Lyle Talbot) and Lt. Bob Lawrence (Steve Reeves). Through their discussion, the viewers learn that her brother Don Gregor (Clancy Malone) had been arrested for carrying an unlicensed handgun. She has just posted bail for him, and the two officers warn her that she would forfeit if her brother fails to show up for his trial. They release her brother, but they refuse Don's request to return his handgun. As the Gregor siblings leave, John Muses about the son of a great doctor being a jerk. Lawrence suggests it could be a result of the "sins of the father".[2] Johns suspects the young man was an associate of gangster Vic Brady (Timothy Farrell).[2]The Gregor siblings return home and Don immediately heads for the liquor cabinet in the living room, pouring himself a drink. He then reminds Marilyn that he is a legal adult, and claims to know what he in doing. Both statements aim to prevent Marilyn from lecturing him on his behavior. They briefly argue and she breaks his glass. Afterwards, Don opens a book safe and retrieves a hidden revolver. As he prepares to leave, Don has a chance encounter with his father Dr. Boris Gregor (Herbert Rawlinson) at the front door. The son exits into the night, while the father enters the home.[2] As his daughter pours a drink for him, the Doctor reveals that he is already aware of Don's association with Vic Brady and his recent arrest. Inspector Johns had notified him with a phone call. But he is not particularly worried, feeling that everything will work out in the end. He blames Don's current behavior on the premature death of Mrs. Gregor and his own upbringing having had the unintentional effect of spoiling the boy.[2]While Marilyn expresses concern over the influence of Brady on Don, her father continues to drink. He then heads for the book safe and discovers that the revolver is missing. He seems aware of his son's secrets, despite his apparent denial concerning his criminal tendencies.[2] The scene shifts to the Hunters' Inn, a bar in Temple City, California, where Don and Brady meet. Don receives his share of the money for his role in a recent robbery. They are then joined by Johns and Lawrence, and briefly "cops" and "crooks" (as they call each other) drink together. The policemen provoke Don into a confrontation, and he knocks over Johns' drink. As the officers intended, this gives them the excuse to frisk him. They fail to find the revolver, as he had earlier offered it to Brady for safekeeping. John orders both criminals to leave the bar and they obey.[2]Outside the bar, Brady chastises Don for his impulsive behavior with the officers. Don wants revenge against Johns, but Brady dismisses the idea and reminds his partner that they have other plans. They are going to rob the payroll of the Monterey Theatre, though Don has his doubts about the plan.[2] At the Gregor House, Marilyn has changed into her nightgown while her father sleeps in an armchair, probably drunk. She wakes him up to discuss their concern over Don's nocturnal activities. The father states that he can't see his own son as a wrongdoer. But he also expresses guilt over his own failure as a father.[2] In the theatre, Cotton Watts performs in blackface. After his act, which involves comedy, dancing, and orchestra music, the theatre closes for the night. Brady and Don break into the closed theatre and ambush the nightwatchman (Bud Osborne).[2]The nightwatchman is forced at gunpoint to open the safe for the criminals. At this point Miss Willis (Mona McKinnon), a bookkeeper, end her shift and attempts to leave the building. She startles the criminals, and the robbery starts having casualties. Don shoots and kills the nightwatchman, while Brady shoots the fleeing woman in the back. Afterwards Brady collects their loot while Don seems to be in shock over his own actions. The two criminals flee while police sirens are heard approaching the theatre. A car chase scene follows, with the driving Brady managing to lead their car to safety.[2] At the theatre, a doctor examines the wounded Willis, while Johns receives the basic information on the case: robbery, murder, and attempted murder. The nightwatchman is identified as a recently retired veteran of the police force, who took his last the job just to relieve his boredom. The officers decide to treat this case as one involving cop killers.[2] The press has already arrived at the murder scene, in the person of a female reporter (Regina Claire) and her photographer.[2]Brady leads Don to the residence of his gun moll, Loretta (Tedi Thurman). While he explains their situation to her, Don leaves unnoticed. When Loretta notices his absence, Brady decides to search for him.[2] The following night, Don wanders the streets until deciding to visit his father's office. He confesses the murder to his father, and the doctor urges him to surrender to the police. The guilt-ridden Don agrees to do so eventually, but wishes for more time to think things through. His father helps him escape the arriving police. While fleeing Don is captured by Brady, who drives him back to Loretta's residence. The three of them listen to the radio, where the case of Paul McKenna (the nightwatchman)'s murder is covered and both their names are announced as murder suspects. Also mentioned in the broadcast is that Don is the son of a famous plastic surgeon.[2] Don repeatedly expresses his decision to surrender and face the consequences of his actions. Fearing for his own safety, Brady kills his partner. The corpse is temporarily stored behind a curtain.[2]An argument between Brady and Loretta follows. She accuses him of destroying everything and everybody that comes in contact with him, while Brady reminds her that he once rescued her from the gutter. He insists that she should stay by his side to the end. The two end the argument in an embrace. At this point, Brady conceives a plan to elude the police by undergoing plastic surgery.[2] He contacts Dr. Gregor, claiming that he is holding Don hostage until plastic surgery is completed. The doctor decides to have Marilyn assist him, since she is a trained nurse.[2]Days later, Lawrence attempt to romance Marilyn, with the ulterior motive of seeking further information on Don. She coldly turns him down. Later than night, Brady, the doctor, Loretta, and Marilyn gather in preparation of the operation. Brady expresses his distrust of the Gregors and has to be convinced that anesthesia is necessary. With Brady sedated, Don searches Loretta's residence for a water basin. He finds it, but also finds Don's stored corpse. He keeps this a secret and maintains a facade of calmness while performing and completing the operation. He claims that the bandages covering Brady's face have to stay on for two weeks. The necessity of a second visit saves his life and that of his daughter, as Loretta had orders to kill them both once the operation was over.[2]Two weeks later, Brady and Loretta arrive to the Gregor residence on schedule. But so do Johns and Lawrence, who were both summoned by the doctor. They want to know who the bandaged man is. When Brady's bandages are removed, his new face is revealed to be modeled after that of Don. Besides the Doctor, everyone else considers him to be the wanted murderer. And the Doctor claims that the man is his son. A horrified Brady attempts to flee and is killed in a shootout with the police. His dying body falls into a swimming pool.[2]
Output: Question: Who summons Marilyn Gregor to the police station?, Answer: Dr. Gregor