Slanted, quirky, lovable, and typically North German: Thies Detlefsen's twins Telje and Tadje embark on their autumn class trip to Amrum with the 10a class of Theodor-Storm-Gymnasium. On board are rookie teacher Vanessa Loebell, the "totally sweet" trainee Manuel Scholz sporting a fashionable pirate scarf, and class teacher Dr. Niggemeier. The crossing is extremely stormy, but the students take countless selfies and shaky video clips—until one of them discovers a body: young sailor Bent Blankenhorn is found murdered on the upper deck. It's code red for Thies and KHK Nicole Stappenbek, who immediately begin their investigations on the island shrouded in autumn fog.