Not a bit of blue blood

During the filming of a fairytale movie at the Klášterec castle, one of the exhibition's most precious exhibits is stolen. In the course of the investigation, a seriously injured man is found near the castle, and shortly afterwards, detectives discover the body of a young girl in one of the halls. What was she doing there, and how did she get into the locked building? The police are working with the theory that she witnessed the robbery and had to be eliminated, but perhaps the whole affair unfolded completely differently…