Zoe Ballentyne, the nine-year-old daughter of an invalid mother, meets “Tuppy” Holt, a new neighbor’s boy, and the children fall in love. “Tuppy” writes his proposal on an old piece of wrapping paper, which Zoe treasures all her life. Zoo’s mother dies and Zoe goes to live with her aunt, who is a social climber. Fourteen years later, “Tuppy,” now grown up and called by his real name, Dudley Holt, falls in love with Zoe, whom he does not recognize as his childhood sweetheart. Zoe marries him under pressure of her aunt. Dudley on the wedding day suspects that Zoe doesn’t love him and confronts the aunt with the lie she told him, that Zoe did love him. Zoe overhears, and disgusted at her aunt’s treachery runs away from her husband and resumes her maiden name of Ballentyne. He pursues her and finds her in the city in time to save her twice from the attentions of two objectionable men. She thanks him but tells him she doesn’t love him and that she will free him whenever he meets a girl he loves. She goes to St. Louis as social secretary in the family of the Razors, a family of newly rich brewers. She finds them expecting the arrival of Dudley Holt, who is an old friend of the family and of whose marriage they have not heard. Mrs. Razor wants him to marry Claire, their daughter. Dudley, upon arriving agrees to help Claire to elope with Bret Jordon, a young man to whom Mrs. Razor objects. Zoe, seeing the development of the plot, thinks that Claire and Holt are going to elope. She warns the Razors just as Claire is escaping. Holt sees that at last his wife has realized that she loves him through her jealousy for Claire. He confronts her with her love for him. She denies it and shows him his boyish scrawl on the old brown wrapping paper, and says that she loves “Tuppy.” He is delighted to inform her that he is “Tuppy,” her childhood sweetheart.