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?