Belle Johnson, a flirtatious widow in Paris for the carnival season, finds that the marriage of her sister Grace and Frank Morley is headed for trouble. Frank is very absorbed in his business, thus Grace has begun an affair with the handsome Sir Lionel Heathcote. Belle tries to save her sister from eloping with Heathcote by making him promise to drop the affair and return to England. Finding them going ahead with their plans, however, she steps in, at the risk of losing the respect of Jim Morley, Frank's brother, who has just returned from South America to ask Belle to marry him. Discovering Belle at Heathcote's apartment, Frank leads Jim to believe that she has been entirely too frisky, but Grace confesses the truth to her husband, rather than see her sister lose the man she loves. Finally, Belle and Jim go off on their honeymoon. It is a lost film.