Etienne Ronsard, a humanitarian surgeon, arrives in Colmar to understand the circumstances of the death of his son Gilles, head of the city’s Crime Squad. As soon as he arrives, he finds the body of a man, dressed in a strange medieval-inspired costume. Anaïs Lacombe, the new head of the brigade, questions Etienne as a witness. When she discovers her identity, she gets confused. Indeed, she believes that Etienne’s son, Gilles Ronsard, is responsible for the death of her fiancé, also a member of the Brigade. He was driving while being on drugs during the accident that cost them their lives.
Etienne Ronsard, although in disagreement with his son for several years, strongly doubts the conclusions of the investigation. Gilles was not an addict. Etienne will get nothing from either the Lieutenant or the Prosecutor: the case is closed. Etienne knows that it is never too late, he hopes to convince Anaïs to open the file of this tragic accident again, and to prove, that the two people they loved did not die for nothing.