At the height of Australian summer, a serial killer dubbed The Shark stalks a beachside suburb, targeting young female swimmers whose bodies are later found on the shoreline. Disempowered and angry at the failures of the police to protect them, two young women are hell-bent on revenge.

Raych has lost someone and will go to any length to discover what happened to her, while Carmen suspects her own disturbing connection to the killer. Together they form an uneasy alliance and, in a moment that changes the trajectory of their lives, Carmen and Raych abduct and imprison the prime suspect. Do they think they can save the day, or are their intentions darker? Can they trust one another's agenda? And when another young woman goes missing, what stops them from going to the police?