Who Shines in Combat is the etymological meaning of the first name Bertille, the younger of the two sisters in the Roussier family, suffering from a serious disability with an uncertain diagnosis. The family lives in a fragile balance around this child who monopolizes everyone's efforts and thoughts, and who could lose his life at any moment. Everyone builds themselves, lives as best they can with the demands of this rhythm and the uncertainties that accompany it. The parents, Madeleine and Gilles, the older sister, Marion. What daily life and what futures for a mother, a father, a couple, a teenager who has become an adult too quickly because of the responsibility of her younger sister? When a new diagnosis is made, the cards are reshuffled and a new horizon emerges...