Moominsummer Madness, Paperback/Tove Jansson

It all began with a hot day in June, and a volcano dropping black ash on Moominmamma's washing. Then a crack appeared in the ground, and Moomintroll's toothbrush slipped straight down into the dark and yawning earth. Then a great flood wave came crashing through Moomin Valley. And that was why the Moomins found themselves a new home, and why they all had so many strange adventures, ones that were odd even by Moomin standards. . .