Based on the prison experience and a play by Dorothy Mackaye, a woman involved in a bank robbery has a love-hate relationship with an evangelist after he turns her in.
Nan Taylor (Barbara Stanwyck) gets a bank to open early so that a gang can hold it up. Afterwards she is identified and arrested. Dave Slade (Preston Foster) talks tough on crime in his radio program; but knowing Nan from childhood, he speaks for her rights. He gets the district attorney to parole her to him; but when she admits she was involved in the stick-up, he changes his mind. Nan confesses and gets 2-5 years at San Quentin.
As a "new fish" she turns off the radio, not wanting to hear Slade's program. Suzie (Dorothy Burgess), who likes Slade, argues with her; but Linda (Lillian Roth) teaches Nan about prison life. Dave Slade wants to visit Nan, but she refuses to see him and rips up his letters. Linda sings "If I Could Be with You." Suzie tells Nan that Slade could help her. Lefty visits Nan and tells her that Don and Dutch were caught and sentenced to 20 years in the same prison. They plan to break out, and she sends them a map to her cell. Nan writes Slade he can visit her, and she makes a soap impression of the master key. Nan hits Suzie and loses her privileges for a month; so Slade is turned away. Suzie is getting out and says good-bye to Nan. Nan makes an outline of the key and puts the letter to Lefty into Slade's pocket during his visit when he kisses her. She tells Slade he was right, and she was wrong. Slade finds the letter and mails it; but the letter is forwarded to the county jail and discovered by authorities. As Don (Lyle Talbot) and Dutch work their way in the sewer to Nan's cell, the guards arrive and shoot them. The warden tells Nan she must do her full five years without privileges, and she vows to get even.
When Nan gets out of prison, she attends a Slade revival meeting; but she is seen by police detective Tracy and Suzie. Slade meets Nan in his office, while Suzie looks in the keyhole. Nan shows Slade a photo of the two men killed and asks why he didn't mail the letter. Slade says he loves her; but Nan shoots him in the arm. Slade covers it up, and Suzie's claim she saw it is not believed. Slade tells Tracy they are getting married, and Nan agrees to be wed.
This hard look at women in prison raised objections in the Hayes office, but the code was not cracking down yet. The relationship between Nan and Slade explores attitudes toward crime, forgiveness, and responsibility. Stool pigeons and the fanatical Suzie are shown unfavorably as is usual in prison culture.