Clues takes on a case he didn't expect: the super smart Marie needs his help! For weeks now, she has noticed a mysterious van following her everywhere. Clues finds it hard to believe that Marie has no idea what the strange people following her want. Nevertheless, he doesn't hesitate for a moment; he immediately starts the investigation. And when suddenly a kidnapping happens right before his eyes and Marie is left with a blackmail letter in her hands, the case takes an unexpected turn.