Spring 1963. Terror reigns in the capital. In one month, 4 young boys disappear without leaving a trace.

Thanks to the recklessness of a young boy, Léo-Paul Dion is arrested. He is forced to make disturbing confessions about his victims.

Me Guy Bertrand, a lawyer hitherto unknown, defends the “Monster of Pont-Rouge" and tries to save him from the death penalty.

Will Léo-Paul Dion escape the death penalty? Ten years later, the first serial killer in Quebec will bequeath his memories to his lawyer.