Victor Lessard, his partner Jacinthe Taillon and rookie Loïc Dubois are trying to solve the murder of Judith Harper, subdued to a strange torture instrument. Meanwhile, officer Nadja Fernandez witnesses the suicide of André Lortie. On the same day, the lawyer Philip Lawson receives at his firm a mysterious letter with a drawing of a Hangman, which has a clue that makes him nervous.
