Allison Long is acquitted on charges of poisoning her father but then her benefactor is poisoned. Reporter Duffy Giles has faith in her innocence.

Allison Lang, a beauty parlor operator on trial for the Mamaroneck, New York murder of her father, who died after drinking milk containing poison, is awarded a controversial not-guilty verdict. Duffy Giles, the only reporter who wrote stories defending Allison, secretes her away from his competitors in the courthouse men's room so that she can sign an exclusive contract for a front-page story of her life. She slips out, because she believes that Duffy does not really think she is innocent, and amid the throng of the crowd, she is hastened into a limousine by Mrs. Martha Hargraves, a wealthy patron who has a collection of eccentrics housed in her Tarrytown home. Allison accepts Martha's offer of lodging until the hubbub dies down, to the disgust of her husband Jerome's sister Henrietta, an acrimonious spinster. One night, Allison, whom Mrs. Hargraves introduces to friends as Angel Reeves, finds an eccentric little man at the door, whom she recognizes as Dr. Cotton, her father's doctor. Dr. Cotton, whose antic actions and poetry frighten Allison, turns out to be the half-brother of Jerome. The doctor, who, if left to his own devices, will unscrew the legs to every chair because he believes he has glass hips and thus cannot sit, has escaped from Dr. Hall's private sanitarium. Duffy, with his own eccentric pal, Dr. Felix, snoops about the Hargraves house. To protect Martha from the disgrace of having Dr. Cotton's connection to the family reported, Allison agrees to give Duffy her story after a masquerade party that night. At the party, Allison overhears Jerome tell Henrietta that Martha has added a codicil to her will making Allison a beneficiary. After Allison fixes warm milk for Martha and Jerome, Martha is found dead from poisoning, while Jerome revives. Allison is arrested and Duffy, who has now lost his job, visits her in prison to help. He infuriates her, however, when he says that he suspects Dr. Barth, who received money for research from Martha and had been developing an affection for Allison. Duffy and Felix sneak into the sanitarium to learn about Dr. Cotton. Pretending to be emissaries sent by the Nobel Committee, they tell the "honored" doctor that to be eligible, he must have committed at least four premeditated murders. After Dr. Cotton takes credit for killing, among others, Allison's father, Duffy coerces the district attorney into a meeting with Dr. Cotton, Jerome, Dr. Barth, Henrietta and Allison. Duffy proves that Jerome poisoned himself and Martha after taking Dr. Cotton's antidote first. Jerome admits killing his wife because he was frustrated that she was squandering her fortune. He then jumps through a window to his death. Allison follows Duffy into the men's room, where he first gives her the cold shoulder but ends up embracing her.