Sophie Moreau and her husband Christian, a teacher, live in Briançon. The couple is going through a painful ordeal as their baby suffers from a serious genetic disease. But instead of uniting the couple, the dreadful experience pulls them apart. Christian, on his part, resigns his post and settles down in Marseilles in order to be closer to the baby. As for Sophie, who feels guilty of transmitting the disease, she shuts herself up in her apartment to take care of their older daughter. In the hospital where the sick child is being treated, Christian gets to know Virginie, a single mother whose daughter Noémie is slowly dying of an incurable disease...