While Athena becomes the new Head of Homicide and Dimitris mourns the loss of his beloved Tonia, a deadly explosion forces the Department to regroup and take action.

The crisis in Apostolos's relationship with Eleni escalates. At the same time, while the police interrogate those involved in the explosion, the appearance of people from the past complicates things even more.

Forensic results turn everything upside down in the explosion case, leading to yet another impasse. Faced with new information, the police implement a plan to shake things up.

The police finally achieve a major breakthrough in their investigation, thanks to the help of not only Dimitris Lainis but also some unexpected allies.