Mika, heiress to a Swiss chocolate company, is married to celebrated pianist André and stepmother to his son, Guillaume, whose mother died in a car wreck on his tenth birthday. Their lives are interrupted by the unexpected arrival of Jeanne, a young woman who has learned she was almost switched with Guillaume at birth.

Valentine, a student model in Geneva, struggles with a possessive boyfriend and a troubled family. When she runs over a dog, she discovers that its owner, a retired judge, is illegally wiretapping and eavesdropping on his neighbors' phone calls. Although Valentine is outraged, she develops a strange bond with the judge – and as the two become closer, she finds herself caught in the middle of events that could change her life.