The eldest waif in an orphanage, Mary Murphy steals a dress and three dollars, then escapes to the city. Grosset, the superintendent of the institution, steals $10,000 on the same night, and Mary is suspected of the theft. Mary manages to get a job as assistant to entomologist William Saxton, after she changes her appearance because the Professor dislikes pretty and fashionably dressed young ladies. Saxton's nephew David sees Mary's true beauty, however, and falls in love with her. Grosset arrives at the Professor's house and threatens to expose Mary. Mary discovers Grosset robbing the safe, but he places the blame on her. Saxton was actually hiding behind the curtain the whole time and heard the truth. Grosset is arrested, and Mary weds David.