Anne is a lawyer specializing in juvenile law. She lives a comfortable, middle-class life with her husband Pierre and two adopted daughters. One day, Pierre's 17-year-old son from a previous marriage moves in with them. He is a rebel. Anne wants to understand his behavior, and in the process, the two grow closer. They quietly put their heads together - magnetically drawn to each other, they kiss, and then have sex for the first time. A passionate affair ensues until Théo reveals the secret on a trip with his father. Anne has her back against the wall - and denies everything.