Paul Craig (Arthur Shirley) is an aviator-inventor who becomes blind due to overwork. He stumbles into a room as a person is being killed by foreign agents – who decide to let Craig live because he cannot identify them. The murder is part of a plot to overthrow the monarchy of fictional Ruvania. Paul regains his sight and marries Angela (Grace Glover), whose brother was killed by the gang, and who is the ward of Carlo Gelmini (George Bryant), head of the gang. Angela lost her memory with the shock of her brother's death but manages to recover it and help Paul save Ruvania.
