Prudence's ( Olive Thomas ) parents send her from their Pennsylvania Quaker colony to a fashionable girls seminary, hoping she can learn about the devil's tricks, instead she engages in girlish pranks, but uses her pure appearance to escape blame. Later, Prudence visits her New York aunt, a society matron, and soon attracts an array of male admirers. She falls in love with wealthy Grayson Mills, but John Melbourne, who lives off of his wife's wealth, plots to seduce her. After Melbourne loans Prudence $200 to pay a gambling debt, he forces her to go to a roadhouse by threatening to show her stern father her canceled check. At dinner, Prudence produces a love letter which Melbourne had earlier written to an actress, and says that if she is not back by midnight, her hotel clerk will show Melbourne's wife his nineteen other love letters. After Melbourne hurries her back, he discovers that she only had the one letter. Prudence now becomes engaged to Grayson.

The relatives of dying Edward Woodruff, Nina Leffingwell, her brother Frederic, and her cousin Basil, whom she wants to marry, scheme to inherit Woodruff's wealth. Since Woodruff continually calls for an imagined granddaughter, the child of his daughter who died before they could patch up a quarrel which estranged them, Nina gets Doll, a Follies girl, to impersonate the granddaughter, try to endear herself to Woodruff, and thus inherit the money. Doll would then be paid off and the relatives would get the inheritance. When Doll's administrations cause Woodruff to recover, Nina sends for Woodruff's grandson Ned, whom he disowned for marrying beneath him, hoping that Ned will send Doll away. When Ned seems to fall in love with Doll, Nina tells Woodruff that Ned and Doll are secretly meeting in the estate lodge. Woodruff investigates and finds that Doll and Ned are married and have a baby boy. Delighted, Woodruff forgives Ned.