As part of his presentation to the jury, the defense attorney for accused murderer Helen Mason tells the story of his client's tragic adolescence: As a high school student, Helen, whose mother strongly disapproves of formal sex education, accompanies her boyfriend Jimmy to an Ohio drinking club and, after stripping behind a curtain as part of her club initiation, becomes drunk. While intoxicated, Jimmy seduces Helen, and a few weeks later, Helen discovers that she is pregnant. Unable to confide in her judgmental mother, Helen decides to elope with Jimmy and move to New York City. On the way, a penniless Jimmy tries to rob a gas station but is shot and killed by the proprietor while fleeing with Helen. Although Helen escapes the police, she loses her baby a few months after arriving in New York. Broke and depressed, Helen contemplates suicide but is saved by Bill, an unemployed newspaper reporter. After Bill and Helen marry, Helen, now using the name Wilson, finally lands a job as a dancer at the Forty Club. Determined to find his own work, Bill leaves Helen but vows to return as soon as he is financially stable. Helen, however, is tracked down by the police and is recognized by Alfred Brent, the club's womanizing publicity agent, who was also a witness of Jimmy's attempted robbery. Helen leaves the club before the police arrive and moves into an apartment building run by the kindly Mrs. Wagner. To Helen's relief, Mrs. Wagner's teenage daughter Betty finds her work as a dance instructor in a neighborhood school. Soon after, however, Brent spots Helen leaving the school and, aware that she is still wanted by the police, arranges for her and her dance students to attend a wild party hosted by Marie, a notorious madame. At the party, Brent threatens to turn Helen over to the police if she refuses to cooperate with Marie. Terrified of prison, Helen agrees to "entertain" one of Marie's guests, but tries unsuccessfully to prevent Brent from seducing Betty. After Betty is fatally injured during an illegal abortion, her mother accuses Helen of murdering her child. At the same time, the local police, suspicious about activities at the school, discover Helen's identity and prepare to arrest her. Accompanied by an unsuspecting Bill, who is now a crime reporter, the police burst into Helen's apartment just after she has shot Brent for ruining Betty. With his recitation of Helen's story complete, her defense attorney accuses Helen's mother of parental neglect and insists that his client is blameless. Although the jury is sympathetic to Helen's action and finally votes for acquittal, a frantic Helen jumps to her death moments before the verdict is read.