Black Medusa.

Nada is a young woman leading a double life. During the daytime she’s quiet and reserved, but after dark she dives into the nightlife of Tunis and picks up men. First, she lets them tell their stories – as she doesn’t speak, she acts as a kind of confidante – then beats the hell out of them. When a new colleague, Noura, arrives at her workplace and Nada finds a mythical knife at the home of one of her victims, events are unleashed over which Nada has less and less control.