In Lausanne, the aspirant pianist Jeanne Pollet has lunch with her mother Louise Pollet, her boyfriend Axel and his mother. Lenna leans that when she was born, a nurse had mistakenly told to the prominent pianist AndrÃ© Polonski that she would be his daughter. AndrÃ© has just remarried his first wife, the heiress of a Swiss chocolate factory Marie-Claire "Mika" Muller and they live in Lausanne with AndrÃ©'s son Guillaume Polonski. Out of the blue, Jeanne visits AndrÃ© and he offers to give piano classes to help her in her examination. Jeanne becomes closer to AndrÃ© and sooner she discovers that Mika might be drugging her stepson with Rohypnol. Further, she might have killed his second wife Lisbeth.