A former Annapolis cadet is thrown out of the Naval Academy for cheating on an exam. Of course he was framed, but he must enlist in the Navy to clear himself. Meanwhile he and his sweetheart search for a buried treasure on Lost Island, which everyone is after.

A silent 15-part movie serial.

Joyce Tolliver, whose nickname is Muggsy, plays baseball, fights and swears with boys, and is severely punished by her elders. When she grows up, she is disguised as a boy, and sent to live with a wealthy old uncle, Leslie Bolton, who hates women. Her ruse works perfectly until she falls in love. When Bolton e discovers that his supposed nephew is really his niece, he orders her out, but after he realizes that he cannot get along without her, he sends for her to return.