When Henry Clay Willard refuses to allow his athletically inclined daughter Mary to attend a prizefight, she goes to the bout dressed in her brother's clothes. Next to her sits wealthy businessman Anthony Fry, who, believing that opportunity knocks only once, decides to give the "boy" his big chance. Anthony takes Mary to his apartment, where the house detective, troubled by the "boy's" strange appearance, begins an investigation. A series of misunderstandings follows, during which Anthony's visiting friend, Johnson Bowler, nearly loses his new wife Beatrice, who arrives unexpectedly to discover a woman in the apartment, and finally, Mary's father is called. Upon his arrival, all is explained, and Anthony and Mary decide to take advantage of the strange opportunity that brought them together.