Doctor Samuel Rayner, Superintendent of the American Skin and Cancer Hospital, is sent abroad to purchase a half a million dollars' worth of radium. He leaves his son, Robert, in charge and takes Betty Weston, a pretty nurse, with him to dress the radium burns on his hand, which has to be done daily. Incidentally he hopes to break up the growing intimacy between Betty and his son. Mallet, a hospital orderly, drops a hint to a band of international crooks, and they follow Doctor Rayner to get the radium. In Berlin a desperate attempt is made to secure the precious material, but thanks to Betty, is foiled. Turner and Crosson, members of the gang, keep on the trail of Dr. Rayner and Betty, and board the same steamer to America. During the voyage Crosson manages to obtain the case containing the radium, and unprotected from its deadly rays, becomes blind. Keeping quiet about their loss, the doctor and Betty hear of Crosson's blindness and at once know where the radium is. Betty, with the aid of a little chloroform, recovers the radium. Turner is furious, and sends a wireless ahead, which results in Betty and Dr. Rayner being kidnapped upon their arrival in New York. Crosson gets worse, so Turner and Mallet send for a doctor, who calls a specialist. Dr. Robert Rayner. son of their prisoner. Meanwhile, Turner and Mallet go to a nearby saloon, where they get to quarreling over the disposition of the radium, and Mallet drugs Turner. He then returns to the gang's headquarters and meets Doctor Rob Rayner. He and the crook have a desperate struggle. Turner, who has recovered consciousness, enters, and had it not been for the intervention of Betty would have killed Rob. The police are called, the gang taken away to jail, and their captive released. In consequence of this unexpected turn of affairs, Rob and Betty gain his father's consent to their marriage.
—Moving Picture World synopsis