Catherine never stopped believing in the innocence of her son, accused of murder. 15 years after his conviction, everything changes. The wife of the former chief of police claims to know the real murderer. Does she hold the key that will clear her son?

The death of a witness creates a stir in St-Bruno. Was it an accident, a murder, or a suicide? One thing is certain; if they wanted to prevent this witness from speaking, it is because a criminal is still on the run.

The autopsy confirms that the witness was murdered and casts doubts on the Parenteau case. Does Bing, a major crimes investigator, have good reason to believe that the investigators of the time, including his own father, hid or manipulated evidence?

Bing and Catherine accumulate more and more credible evidence on Alexander's innocence. At the same time, the interrogation they undergo becomes complex. When will we know the nature of the investigation for which they are questioned?

Bing and Catherine hit a wall. The BEI accuses them of having manipulated former witnesses, Alexandre wants to plead guilty, and Bing is expelled from the investigation. Clearly, someone wants to put a spoke in their wheels, but who?

Bing examines the contents of the boxes of information related to the Parenteau case that his father had hidden. New suspects surface and the evidence is undeniable; the murder of Jérémie Parenteau is akin to a conspiracy.