Since her parents death, hobby-detective Trudi lives with her young aunt Julia. When a nearby Turkish restaurant is smashed one night, everybody assumes by default an act of racism. Trudi however did notice a strange guest named Mangold there the day before. Also the caretaker seems very keen on getting the restaurant out of the building. The police and host Kemal don't seem particularly interested in investigating the event, so Trudi starts her own investigations in the style of Sherlock Holmes, with the help of her friend Tom and runaway Rollo.