At Photo studio P. van Straaten, two models, Jacky and Penny, are dressed in Lederhosen to film a muesli ad. A missing prop, William Tell's arrow, is found lodged in the chest of Mabel de Ruijter, the studio's owner. Inspector Jeanine Kaart and her assistant De Bruin round up the suspects. Mabel's widower Ralf is already busy flirting with Penny. Nephew Paul, the photographer, is planning to marry Jacky, while his assistant Suzanne also has a reason to despise Mabel.
—The TV Archaeologist