While off on a class trip, ""Die Pfefferkoerner"" (""The Peppercorns'), the detective kids from Hamburg, experience a thrilling adventure in the mountains of South Tyrol revolving around a ""curse' that strikes fear into the residents on a mountain farm. The children track down evidence of a crime that soon puts their own lives in danger, too. After a barn is set on fire, it soon becomes clear that the child detectives can only solve the case when they work together with, of all people, the one classmate they like the least. When that classmate disappears, the ""Pfefferkoerner"" have to risk everything it takes in a mine and on a cable lift to put the criminals out of business.