Paris, nowadays: Ludo has been devoted to far-left militancy since his adolescence, Lisa is a feminist schoolteacher in a free couple with Yann. After three months in prison, he discovers love for the first time in his life with her. But as Ludo's clandestine life catches up with him, Lisa learns that the illness that has been weakening her since the summer is cancer. A race against time begins to transmit to him the vital impetus she gave him when they met.