While Luca follows the trail of Luciano Gerace's (Dante Palladino) Camorra clan, Alessandro, trusting his police instinct, decides to "hook up" Melissa. Meanwhile, the rest of the X° Tuscolano deals with the murder of a mother, in which the main suspect is the woman's stepson. The case is complicated by the fact that the only witness is the lady's biological son, an autistic boy with whom no one seems able to communicate. While Luca perseveres on the trail of the Camorra, Alessandro continues to see Melissa in secret, putting his life at risk. The case of the episode instead concerns the alleged suicide of a woman no longer young suffering from cancer, whose "last journey" hides a much more disturbing truth.