Reginald "Reggie" Burroughs' studies at Oxford are interrupted by the news that his dreadfully staid aunts wish him to take charge of his property in New York after his fifteen-year absence. Reluctant to leave his sweetheart, Marjorie Threadwell, Reggie agrees to allow his roommate, nicknamed Mr. Fix-It because of his talent for mending brokenhearts, to take his place as the head of the Burroughs family. Believing that he is Reggie, the aunts inform Mr. Fix-It that he is to marry Olive Van Tassell and that his sister must wed Gideon Van Tassell. Since both women are in love with other men, Mr. Fix-It obligingly refuses Olive and then helps her to win the man she loves, while simultaneously aiding Georgiana with her romance. When he meets Mary McCollugh and her many little brothers and sisters, Mr. Fix-It brings them all into the Burroughs' mansion, where they proceed to soften the old aunts' hearts. Following a lovers' misunderstanding as well as several adventures, Mr. Fix-It wins his own sweetheart, Mary.