American gambler Philip Eden, who has ambushed his young daughter Alice from his estranged wife Florence, loses all of his money playing roulette in a French casino. In spite of Philip's sporadic income, he and Alice pledge to maintain an attitude of "wise foolishness" and to face the future together, one day at a time. Alice and Philip's happy plans are disrupted, however, when Bernice Solon, a jilted lover of Philip's, tracks them to their apartment and reveals that, out of jealousy, she has informed Florence of their whereabouts. Determined not to allow the oppressive Florence to reclaim Alice, Philip ties up Bernice in his apartment and flees to Italy with his daughter. Moments after Philip leaves, a pot boils over on the stove and deadly gas fills the apartment. In Italy, after he has won big money in a casino, Philip is arrested for murdering Bernice. Although he swears his innocence, Philip is returned to France and is tried and sentenced to fifteen years in prison. Without revealing the cause of his sudden departure, Philip bids Alice a tearful goodbye, and Florence, who has recently married the wealthy Mr. Stebbins, takes Alice back to England. Through her nanny, Jenny, Alice writes letters to Philip and tells him that, after an unsuccessful attempt at running away from home, she fell sick and lost the use of her legs. Although concerned about his daughter's plight, Philip refrains from responding to her letters, and eventually Alice stops her correspondence and moves to America with her mother and stepfather. Many years later, Jenny visits Philip in prison and tells him that Alice and the now widowed Florence have moved to Long Island. Jenny also informs Philip that Alice is ill again and desperately unhappy because Florence has prevented her from marrying newspaper man Stephen. Distressed by this news, Philip escapes from prison and heads for New York. There, Philip confronts a surprised Florence, who coldly tells him she has worked hard to stamp out everything in Alice that resembles her father. Thus warned, Philip introduces himself to the invalid Alice as his brother John, and Alice takes an immediate liking to him. Although she tries repeatedly to force Philip to leave, Florence supports his impersonation to protect Alice, whose memory of her father is dim. Later, Philip runs into Stephen, who still loves Alice, prowling outside her bedroom window. Stephen reveals to Philip that Alice's childhood paralysis returned only after Florence stopped their elopement. Determined to restore Alice's happy childhood disposition and health, Philip connives to bring her together with Stephen while Florence is out of the house. Philip describes for Alice the "half-mad cavalier" who was her father. When Stephen asks her to go away with him, Alice refuses, but admits to Philip that she does indeed love him. Philip then accuses Alice of being a coward and eggs her on with calculated insults. After a brush with Connors, a suspicious police detective, Philip buys two tickets to Italy and gives them to Stephen. As hoped, Alice, who has realized the truth of Philip's words, reconciles with Stephen and, while standing upright, confronts Florence with her impending elopement. When Florence blurts out that Philip spent time in prison, Alice suddenly knows Uncle John is really Philip. Philip bids farewell to Alice, saying he has an appointment on the moon, and promises see her in a few years. He then leaves with Connors, sure now that he lives on in Alice.