Join Moomintroll and his friends as they set out to solve a curious mystery in this brand new picture book based on the original stories by Tove Jansson. If you haven´t met a Moomin yet, you´re missing the most magical fun . . . It´s a long, lazy midsummer afternoon in Moominvalley and the whole family are relaxing outdoors. But suddenly Moominpappa´s precious notebook and fountain pen vanish, and the garden starts to feel unseasonably cold. Can Moomintroll and his friends follow the clues and solve this curious mystery?