Marie leaves her family and goes to live in Lyon to study piano at the conservatory. For economic reasons, she shares the large apartment belonging to Emma, a childhood friend, who has been living alone since her father died and her mother left. Marie abides by the strict rules laid down by her flatmate who exerts growing pressure on her. Emma fascinates, dominates and overwhelms her. Marie is torn between her desire for Emma and her need to escape from her. This is the story of their relationship over the course of a year: Emma monopolises all Marie’s attention to the point of suffocating her and Marie lets herself be taken in, losing her way to the point of no longer being able to play the piano.