A corrupt judge attacks a reformer's family.

Corrupt New York night court Judge Moffett is being investigated by distinguished jurist Judge William Osgood, who hopes to rid the legal system of corruption. To thwart Osgood, Moffett removes incriminating papers from his safe and tells his mistress, Lil Baker, to move from her Park Avenue apartment to a cheap neighborhood uptown. Lil's neighbors are taxi driver Mike Thomas and his wife Mary, a happy young couple with a baby. When Moffett visits Lil and discovers that she is being followed by one of Osgood's detectives, he tells her to talk to Mary to see what she knows. Though Mary knows nothing, when she returns an envelope Lil dropped in her apartment containing Moffett's secret bank book, Moffett is certain that Mary is a plant and concocts a plan whereby a man will enter Mary's bedroom while Mike is at work and cause a scene. When the police arrive, they arrest Mary for soliciting and take her to Moffett's court. Moffett appoints crooked attorney Crawford as her counsel and he advises her to plead guilty and receive a five dollar fine instead of waiting for a trial. Mary reluctantly does what he suggests, but instead of a fine, Moffett gives her six months at a workhouse. Next morning, when Mike comes home, his neighbors tell him what has happened, but he refuses to believe that Mary is a prostitute. He takes the baby to Moffett's court to find out the truth and learns that Mary has pleaded guilty and is at the workhouse. Moffett then makes the baby a ward of the court and sends it to an institution because Mike has no one to look after the child. Embittered, and starting to believe the charges against Mary, Mike returns home. He drives Lil to her new apartment after she sees him slug Osgood's detective, who had come to question Mary, then gets drunk. Remorseful the next day, Mike goes to see Mary, who convinces him that she is innocent. When she calls Lil "Mrs. Moffett," because of the name on the bank book she found, Mike realizes that the judge is responsible for everything that has happened. He then goes to an attorney for help, but he is a cohort of Moffett's who informs the judge. Moffett then hires thugs to beat Mike up and put him on a boat to South America. Meanwhile, Osgood calls Moffett to his home to offer him immunity from prosecution if he will help convict others involved. Unknown to Moffett, the judge is recording their conversation on a dictaphone hidden in his cigar humidor. Moffett makes threats against Osgood, then leaves. Later, when Moffett hires a cab, Mike, who jumped ship and swam ashore, is the cabbie. Mike takes him to his apartment, ties him up and slaps him for hours, trying to make him admit his guilt. That same night, a thug who took incriminating papers against Moffett from Osgood's safe returns to steal money and kills Osgood. Next morning, when Mike learns that Osgood has been murdered and Moffett is the prime suspect, he drags Moffett into his own courtroom. The presiding judge wants to hold Moffett over for trial, but Moffett insists on an immediate hearing. The district attorney then plays the recording which seems to prove Moffett's guilt. Because Osgood's broken watch has set the time of his death at 4:00 a.m., Moffett says that he was being held prisoner by Mike, but Mike refuses to corroborate the story until Moffett confesses everything about Mary. Though Moffett is found not guilty of murder, he is later sentenced to ten years in prison for corruption, along with his cohorts, while Mary and Mike resume their happy life.