On leaving work, while Darío Manzano is taking drugs in the car, he receives an unexpected visit from Ginés Chega. At the same time that he points a gun at Darío´s face, he asks about his friend Abraham "El Gitano", whom he accuses of having stolen a lot of money.
Manzano, without knowing what happened, cannot answer anything about it, and Ginés angrily gives Darío a head butt on the nose while threatening him and leaves.
Darío with a broken nose, starts looking for his friend. When he finally finds him, very angry, he reproaches Abraham for stealing from Los Chega, very dangerous people. Trying to find a solution, Darío decides to take Abraham to France so that they will not find him.
That night, during the car journey, Darío suffers a stroke that will cause him to lose control, leaving the road and causing the death of Abraham.
After a few months, the advances in Darío's rehabilitation begin to show results. But everything begins to go wrong due to the accumulation of different events that will put Darío and his family in trouble: defaults with the bank, tensions between them and the imminent sentence of the trial for the accident. To this is added, the pressure from Los Chega to Darío to recover his lost money, since the night of the robbery, Abraham was in the car with Manzano when he suffered the accident.
As a consequence of this, Manzano will live a few hours prior to his entry into prison frantic and full of danger, where he will try to defend, TO THE TEETH OF A DOG, his family.
马赛,一名连续作案的变态杀手在一些富人别墅里强暴女子之后,将被害人殴打致死。乾探路易·施耐德奉命展开调查。施耐德因女儿在几年前的一场车祸中丧生、妻子也终身伤残而心力交瘁,他变成了酒鬼。年轻女子茱丝蒂娜因25年前亲眼见到双亲被残酷杀害而难以克服过去的梦魇,而且她得知凶手即将被释放。她因凶手将获释一事而与施耐德走到一起。本片的导演奥利维埃·马夏尔当过警察,他曾于2004年推出《金银匠滨河路36号》(36 QUAI DES ORFEVRES,司法警察局局址)。《MR 73左轮枪》根据他1981年参与调查的一部真实案件改编,片名指的是马努兰厂(MANURHIN)1973年出厂的“巨蟒”357型左轮枪,法国宪警精锐部队都使用这种武器。