The main character of the thriller "Fatal Defense" lives with her daughter in a big house. The baby is sick, and the mother has to get up at night to give her water. Woman attracts some strange rustle. The door is opened, and an uninvited guest in a mask grows up behind his back. He behaves aggressively, ties the hostess to the chair, but does not harm either her or the awakened girl. Police officers who arrived at the scene say that this is not the first case this week in this town. They advise the victim to learn how to fight, hinting that one day this could save her life.
The woman decides to follow the advice and goes to the self-defense section. It is run by Logan, a strange young man whose methods are distinguished by uncompromising and lack of concessions even for women. On the very first visit, the heroine leaves with bruises on her wrists. Workouts begin, after which the coach arranges for his fierce checks. Ardon begins to suspect that Logan is not all right with the psyche.