Thera Dufre, a former member of a foreign secret service bureau and now in hiding from the government agents, receives a mysterious letter ordering her to take a certain sealed packet, which she has in her possession, to an appointed meeting place and deliver it to DeSerris, a member of the service, whom she has never seen. In the same city is living a Mrs. Irving, who bears a likeness to the secret service woman. DeSerris, who is to identify Thera by a photograph, waits at the appointed place and, by accident, Mrs. Irving passes. DeSerris accosts her and demands the packet, but, of course, being ignorant of the entire affair, she tells him that he has mistaken her for someone else. DeSerris believes that she has determined not to give up the packet and forces his way into her auto. Thera, who arrives just in time to see DeSerris' mistake, decides to escape from the city. Fortunately for Mrs. Irving, the auto arrives home and she escapes from the car before DeSerris can harm her. Irving, a very jealous man, sees DeSerris follow her from the car and refuses to accept his wife's explanations that the man mistook her for someone else. That evening as Mrs. Irving is putting their little daughter to bed, the child pleads for her doll which she had left in the summer house. Mrs. Irving goes to get it and is accosted by DeSerris, who is on the premises and who again demands the packet. They are seen by Irving who goes after them with a gun. DeSerris conceals himself and Mrs. Irving tries to wrest the gun from her husband. In doing so, the gun is discharged, and their child, who had decided to get the doll herself, is hit Thera, on the way to the depot to catch her train, is struck by the Irving's auto carrying the child to the hospital, and, although not seriously hurt, Irving sends her back to his house in care of the butler, who is in the auto. Irving notices the resemblance of the woman to his wife. Arriving at the hospital the child is rushed to the operating table. Thera is taken to the Irving home, but feeling that she is able to proceed to the depot, is on the point of leaving when she sees Mrs. Irving and recognizes her. The servants leave the room and Thera is on the point of fleeing when through a window. DeSerris enters the library. Mrs. Irving confronts him when he again demands the packet. Thera watches from her place of concealment. Mrs. Irving struggles with him when he threatens to shoot her and Thera kills him with a shot from her revolver. Mrs. Irving collapses in a dead faint. Locking the doors to bar out the servants, Thera sees a chance to escape the consequences of the crime, and places the gun beside the unconscious form of Mrs. Irving and is on the point of leaving through the window when the phone rings. To allay suspicion Thera answers the phone and over the wire comes Irving's voice saying that the child will recover and begging forgiveness for his jealousy. Realizing that Mrs. Irving would be torn away from her family and found guilty of the crime, Thera decides to remain and accept the penalty. Unlocking the door she admits the frightened servants and tells of the killing. Then she waits calmly for the arrival of the officers.