Chocolate Grandfather

In the Norwegian city of Bergen lives a quite ordinary Norwegian family: mom, dad, six-year-old Martin, and his older sister Matilda. But everything changes, and life suddenly fills with adventures when their grandfather Oscar comes to visit, whom the children have never seen before. Oscar is aptly nicknamed Chocolate Grandfather, as he is a terrible sweet tooth and cannot live without candies and chocolate. And he also—whether you believe it or not—has the ability to walk on the ceiling, what an unusual grandfather! At the same time as Oscar, the Paulsen sisters arrive in Bergen, three rather troublesome ladies who, on the contrary, cannot stand sweets and dream that all the cakes and pastries in the city become bitter or salty.

Why do they want this, and will they manage to ruin the annual city sweet fair, or will someone thwart their cunning plans? How did this exciting detective story end?