Paul, a young biologist married to Anne, meets Virginie who has just been thrown out to the street by her boy-friend Auguste. Paul buys her lunch and in return the girl makes love to him. The next day, he suggests to take her with him to Geneva and to accomodate her at his home. After a few days, Anne and Virginie become quite friendly. They take opportunity of Paul's leaving to go out with Ferdinand, that Virginie just met. Ferdinand makes love to Anne but, once the week-end is over, things become normal again.