It was supposed to be a simple hike. A few hours' stroll in the spectacular Cirque de Mourèze for Chloé, Anna, and Mathieu, her colleague with the devastating smile, as well as Rose, who, completely charmed by the young man, had invited herself along unannounced. But their outing suddenly turns into a nightmare when a stranger appears and takes the group hostage. Dr. Marianne Delcourt is quickly contacted.