Attorney General Robert Sheldon (Warren William) and Ruth Vincent (Barbara Stanwyck), the daughter of Governor Vincent (Arthur Byron), have to keep their marriage a secret when investigator Daniel Breeden (Douglas Dumbrille) uncovers evidence that may show that the governor took a bribe from J.F. Holdstock (Russell Hicks) an embezzling financier he pardoned. Holdstock's private secretary, Willis Martin (Grant Mitchell), who deposited the bribe money in the governor's private bank account, tells Sheldon and Breeden that he knows of no business between Holdstickk and the governor that would explain the money.
Sheldon goes to the Governor's Residence to tell Ruth about the situation, and that he is obligated to present the evidence to a legislative investigation committee. Ruth is certain that her father did not take a bribe, and that Holdstock can explain everything, but they learn by phone from Breeden that Holdstock has committed suicide.
The Governor is concerned about the allegations, but his financial backer, Jim Lansdale (Henry O'Neill) calms him down, and takes him to lunch. Before he does he makes a phone call in which he learns that Sheldon is at the Governor's residence, but he does not tell the Governor this.
In Holdstock's papers, Sheldon finds a typed note which apparently provides a motive for the bribe: "My dear friend Holdstock ... the expense of maintaining my sockfarm has exceeded the income during the year ... the time for the matter we discussed has come. W.H.V." Sheldon rushes to show it to Ruth, and they decide to take it to police headquarters to be compared with a sample from the governor's personal typewriter. Lt. Tom Nigard (Arthur Aylesworth) shows them the comparison: both samples are definitely from the same machine. Ruth returns home to tell her father about the evidence, and he adamantly denies that he wrote the note, giving her his word of honor.
That night, Breeden goes to Holdstock's office, where a very spooked Martin is still working. Breeden tries to calm him down, telling him "You have nothing to worry about, it's almost over. I've seen you through today as I promised, haven't I? ... You were splendid today in Sheldon's office. You just stick to your story and remember that I'm taking care of you."
Ruth goes to Sheldon's apartment to tell him that she's absolutely certain her father is innocent. While she is there, Sheldon's secretary, Hazel Normandie (Glenda Farrell) leaves for the day, planning to meet Breeden, her boyfriend, outside the building. As he walks up to her, Breeden is shot dead. Ruth has seen everything from the window, and knows that Hazel didn't fire the shot, but cannot tell the police because of her secret marriage to Sheldon: if it was learned that she was in his apartment at night, she fears that their marriage will be discovered.
The police investigation of Breeden's murder determines that the gun used to kill him belonged to Hazel, the same gun that we saw Breeden take away from her earlier in the day, saying that he was all the protection she needed.
At a raucous session of the legislature, Representative McPherson (William Davidson), from the party opposing the Governor, accuses both the governor and Attorney General Sheldon of withholding evidence from the investigative committee. They are staunchly defended by Representative Grosvenor (Willard Robertson), but McPherson demands articles of impeachment against the governor and intensive investigation of Sheldon. Ruth observes it all from the gallery.
Hazel is standing trial for the murder of Breeden, with the case about to go to the jury, but Ruth still refuses to testify, knowing that the revelation of her secret marriage with Sheldon would end his career. With little time to waste, Ruth goes to the apartment of Willis Martin, Holdstock's secretary, who appears to be cracking up. Martin admits to her that Holdstock didn't commit suicide, but was murdered, and says that he is willing to tell Sheldon so, but once at Sheldon's office he runs away; Sheldon puts out an alert for the police to pick him up. Now, with no other choice, he and Ruth head to the courthouse, where the jury is voting, and find Hazel's attorney. The judge reopens the case to allow Ruth to testify, and Hazel is acquitted.
The next morning, Governor Vincent is annoyed that Ruth didn't tell him about the marriage, but understands that the circumstances necessitated it. With the governor's impeachment trial due to start soon, Jim Lansdale counsels the governor to resign, but he refuses. Meanwhile, the legislature demands that Attorney General Sheldon resign, but he, too, refuses.
The police find Martin and bring him to Sheldon. Representative McPherson shows up with subpoenas for Martin and Sheldon to testify before the committee, where the existence of the typed letter apparently from the governor to Holdstick comes out. Martin admits that Breeden made him put the letter into Holdstock's files, and then sent him to Holdstock to demand the money he lost in Holdstock's crash. When Holdstock denied he had any money, Martin shot and killed him, and Breeden fixed it to look like suicide. The whole frame-up, according to Martin, is the work of Jim Lansdale, supposedly the governor's friend and financial backer: ever since the governor vetoed a highway bill that would have made him millions, Lansdale had been working to bring down his old friend. It was Lansdale who typed the letter on the typewriter in the governor's study.
As the committee votes to drop the charges against the governor, Lansdale slowly leaves the room and kills himself. Afterwards, in the anteroom, the governor gives his blessing to the marriage of his daughter and Sheldon, and they kiss.