Dorothy Gerard, visiting in Grantwood, a suburb of Washington, receives a letter from her father informing her that he is about to return from California. He mentions robberies that have taken place in Washington and instructs Dorothy to remove certain papers from the library safe. Suddenly Dorothy remembers she has forgotten the family silver. She is further disturbed when she reads of robberies and is dumbfounded to see in the picture of "The Magpie," the robber, almost a replica of herself. She accepts an invitation from Bob Grey to attend a play that evening, and explains that she will be compelled to miss the first act but will be ready at nine. Dorothy arrives about eight. As she enters the house she hears a noise. Creeping toward the portieres, she sees the family silver being carefully packed in a suitcase by a burglar. Dorothy is at a loss how to proceed when the picture of "The Magpie" flashes across her mind and she decides to play the role and capture the burglar. She assumes a carefree air and confronts the burglar. His hand falls on the gun by his side, but he drops it at once to remove his cap. Dorothy explains that she was working on the safe and heard him at work. Knowing the safe contained nothing that would interest the burglar, Dorothy opens it. The crook is amazed and offers to work with her fifty-fifty. Dorothy accepts and "Bill" invites her to visit his den at 49 Water Street and "split the swag." Dorothy suggests that they have a bottle of wine, and the burglar starts for the ice-box. Just before nine he seizes the suitcase and tells her he is going. She realizes she must accompany him if she wishes to regain the silver, and, dropping a note, leaves with the burglar. A few minutes later Bob finds the note. He sees the library in disorder and finds another note reading, "Danger, Dorothy, 49 Water Street." He is about to leave when Kelly, the patrolman, orders him to throw up his hands. Bob pleads to be allowed to go. Kelly laughs. Bob slams him an uppercut which floors the patrolman and he dashes out. At 49 Water Street the burglar and Dorothy quarrel. Dorothy, pretending anger, swaggers to the door, steals the burglar's gun from his pocket, covers the burglar and holds him until Bob arrives. While Bob and Dorothy are rejoicing Bill makes his getaway, but he is captured by Kelly. He tips Kelly off to the Magpie and Bob and Dorothy are captured and locked up. The following morning Senator Gerard arrives and hears of the robbery. He is driven to the police station, is shown the silver and identifies it. Dorothy, Bob and the burglar are being led out to the courtroom when Bob spies the senator and makes a break for him. Dorothy follows and the station is thrown into an uproar. All is explained and forgiven, and only the burglar suffers.