Adapted from Dora Macy's novel, a nurse discovers an attempt to starve children to gain a trust fund and saves the children.
At a hospital Dr. Bell (Charles Winninger) helps Lora Hart (Barbara Stanwyck) get a job as a nurse without a diploma. Miss Dillon (Vera Lewis) tells her the rules, and Hart rooms with Maloney (Joan Blondell). They sneak in late, and Hart finds a skeleton in her bed. Dillon puts them on the night shift, and Hart gets in bed with Maloney. Hart treats the wounded arm of a bootlegger known as Pal (Ben Lyon) but doesn't report the bullet wound as required by law. In surgery Maloney helps Hart stay conscious when the patient dies. They graduate and take the Florence Nightingale pledge.
Hart works as night nurse for a rich family. The day nurse Maloney tells her the children are anemic and only get milk. Hart learns their sister died, and they tell her the chauffeur Nick is horrid. The children say they are hungry, but Mrs. Maxwell (Blanche Frederici) tells Hart not to believe them. A drunk gropes Hart against her will. Nick (Clark Gable) comes in and knocks him out. When Hart tries to call a doctor, he slugs her and carries her to another room. Hart tells Dr. Ranger (Ralf Harolde), who denies there is a problem. She says they are starving and resigns. Hart goes to Dr. Bell, who won't intervene because of "professional ethics." He advises her to go back on that job, and she apologizes to Dr. Ranger. Mrs. Ritchey (Charlotte Merriam) gives Hart $100.
At a drugstore Hart sees her Pal, who notices she got hit. He says he quit the rackets, but she doesn't believe him. Mrs. Maxwell tells Hart she is worried, and Maloney says that Nanny is worse. Hart looks for Mrs. Ritchie at a party and finds her drunk. Hart pleads that Nanny is ill; but Mrs. Ritchie says she is a dipsomaniac. Hart knocks down drunk Mack, while Mrs. Ritchie passes out. Hart calls Dr. Bell and leaves a message that Nick overhears. Pal comes in looking for Nick, delivering booze. Hart asks him to help and sends him out for milk, which he steals, so they can try the milk bath Mrs. Maxwell keeps recommending. A drunk Mrs. Maxwell tells Hart about Nick and Mrs. Ritchie's custody of the children's trust fund. Hart accuses Nick of murder with Dr. Ranger. Nick chases Mrs. Maxwell out. Dr. Bell comes in and advises a blood transfusion. Hart offers her blood. Nick punches Dr. Bell; but Pal makes Nick leave. Dr. Bell tells Hart that Nanny will recover. Hart says she is going to the police, and Pal takes her, saying he told his friends he didn't like Nick, who is taken to the morgue.
Notorious for showing the nurses changing clothes, this dramatic story portrays a bootlegger as helpful and a woman victimized with the use of alcohol. The real heroine is the courageous night nurse, who is not afraid to risk her career to help people in need.