Louise Parke runs away to Paris with her lover Stephen Underwood, but because her mother, Mrs. Treadway Parke, misses her so deeply, she sends a wire announcing her return home. When the boat on which she is scheduled to sail is torpedoed, Mrs. Parke's physician, Dr. Granville, becomes concerned for her sanity and asks Peggy Murray, a newsstand girl who bears a remarkable likeness to Louise, to pose as the missing girl. At first the masquerade is successful: Mrs. Parke is happy and Peggy falls in love with George Landis. Soon, however, Louise returns unharmed, and Peggy slips away quietly. George finds Peggy working in the department store owned by his father and proposes. On their honeymoon cruise, the couple is surprised to encounter two more newly married couples: Stephen has married Louise; and Mrs. Parke has become Mrs. Dr. Granville.
—AFI