The young doctor, spending most of his time in charity work, is particularly interested in the case of a poor mother who must send her child away for its health. This brings him into contact with the owner of the tenement and he endeavors to persuade him to improve conditions. He is refused. But, the owner's daughter has overheard this refusal and she determined to investigate the trouble herself. Her father agrees to her slumming with annoyance. She meets the doctor at the flat of the poor woman, and constant association encourages love. Later the doctor proposes and is accepted. She learns that the child will recover with careful nursing and sends a note to her father stating that she will remain. One night the building takes fire. The doctor and the girl, watching over the sick bed, are warned by the mother. All escape but Dot. The father, who has received word that the tenement is in flames, rushes to the scene and fights to lend aid. The doctor has gone back into the building and after a moment of great suspense he emerges with the girl in his arms. To show his gratitude the owner builds good sanitary tenements, while the doctor and Dot are quietly and happily married.