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 André Polonski that she would be his daughter. André has just remarried his first wife, the heiress of a Swiss chocolate factory Marie-Claire "Mika" Muller and they live in Lausanne with André's son Guillaume Polonski. Out of the blue, Jeanne visits André and he offers to give piano classes to help her in her examination. Jeanne becomes closer to André and sooner she discovers that Mika might be drugging her stepson with Rohypnol. Further, she might have killed his second wife Lisbeth.—Claudio Carvalho, Rio de Janeiro, Brazil

Milka Muller is the general director of Chocolates Muller, who lives in Switzerland with her husband André Polonski, a prestigious pianist, and Guillaume, the son of André. Jeanne Pollet is a young pianist who has not yet begun her studies at the conservatory and who one day discovers that when she was born she was about to be exchanged in the hospital for Guillaume. Determined to know its origins, Jeanne goes to visit André.—Miguel Ángel Díaz González

When the young Jeanne finds out that she could have mistakenly been exchanged, from her cradle, with another newborn (the son of a famous piano player), she decides to contact this family, not really thinking that this could be the truth. After she tells this to the presumed father and the rest of the family, even the son of the piano player starts having more than one doubt about his origins, and all this will lead to the discovery of a murder committed many years before by the second wife of the musician. The story is a pretext to dramatize the misdeeds and the hypocrisy of the French upper class members, shown without pity: the coldness between the family members, hidden by a false happiness; the lack of real feelings; the unbearable 'bon ton' of the mother, and so on.—Anonymous

After the death of his second wife, concert pianist André Polonski remarries his first wife, Swiss chocolate-company heiress Mika Muller. Soon a young piano student, Jeanne Polet, gets the idea that she may be André's daughter. She visits his house in Lausanne, gets to know André's son Guillaume who was born on the same day as she, and starts taking piano lessons from André. Mika Muller keeps serving them her famous hot chocolate, but with some help from a boyfriend conveniently working in a lab owned by Jeanne's mother, it soon becomes obvious to Jeanne that the chocolate doesn't come straight from the family company's production line.—Markku Kuoppamäki