When Charles Wright visits a mountain resort with his son, he meets handsome widow Mary Horton, and emotions long silent in both speak up. To enliven the situation, worthless young Fred Wright falls in love with Mrs. Horton's daughter Vivian, who for the sake of her brother Phillip, Fred's good friend, Vivian permits the attention for a time. Fred's acts are contemptible: he possesses no morals; he even takes advantage of his position to gamble with and win a large sum of money from Phillip and uses the I.O.U. he secures to hold over the boy's head when he resents his attentions to his sister. But Fred carries his attentions to the point of insult one evening. Phillip observes this and flies into a passion. There is a fight. Fred escapes in his canoe. Phillip follows in another and from where she stands, Vivian sees the two men fight in the water. Fred sinks. Phillip returns to his sister and, fearful of punishment, they decide to keep Fred's death a secret. When his son does not return, Mr. Wright employs a private detective from the city. The detective, Noble, arrives and is introduced as an old friend. Quietly he takes up the work of learning the whereabouts of the dead boy. He has the lake dragged. The body is brought up and in the clothing is found the I.O.U. slips, evidence that points to Phillip as the murderer. Meanwhile, Vivian and the detective have been keeping company and falling in love, creating a trying situation for herself and Phillip. Vivian is determined that Phillip shall not be captured and she takes steps to secure the evidence that has been secured against him. In order to accomplish this, she dresses in boys' clothes and, when the night is dark, starts out on her mission. She is shadowed by the detective who believes her a man, the real murderer of young Fred. Sneaking up behind her he fastens the handcuffs upon her. Then it is that he learns her identify, and it is then that the girl, to protect her brother, assumes the guilt of killing Fred. There follows a battle of emotions in the heart of the detective. Should he turn the girl loose in response to his heart, or should he do his duty and force her to stand trial? His love triumphs. He turns the girl loose, determined to never see her again. Meantime, Phillip's innocence is proved by an eyewitness to the fight in the canoes. Phillip gives himself up, confident that the court will be lenient with him. At the end of the story Phillip is taken to the city for trial and we leave to the imagination of the spectators the final conclusion, suggesting to them, however, that older folks will marry and that Noble and Vivian will become reconciled.