Francois, an architect together with Florence and Caro, his two sisters spends a weekend in their family house, where they spent their childhood. Soon, a railway for a express train will be built at this place, so the house will have to be demolished. In the past there were some things that he would prefer to hide, but he has many difficulties to do this. It is a happy reunion, but the reunion of being united by the bonds that will open. Francois and Florence immediately resume gestures, frankly sensual gestures, which he experienced with annoyance and which she persistently sought. Then they will reveal to Caro, the eldest, that they loved each other with forbidden love.