Luca (Claudio Santamaria), a passionate musician living in Prague, is consumed by an intense, destructive jealousy regarding his law student girlfriend, Klára (Laura Chiatti). Convinced that she is sleeping with her university professor, Luca hires Denis (Iain Glen), an experienced private detective, to follow her every move and capture proof of her infidelity. As Denis monitors Klára, he becomes fascinated by her, blurring the line between investigator and subject. The situation spirals into a web of surveillance, manipulation, and unexpected attraction that forces all three to confront their true motives.