About the book: 2017 / A completely ordinary Norwegian family lives in the Norwegian city of Bergen: mom, dad, six-year-old Martin and his older sister Matilda. But everything changes, and life is suddenly filled with adventures when Grandpa Oscar, whom the children have never seen before, comes to stay with them. It’s not for nothing that Oscar was nicknamed the Chocolate Grandfather, because he has a terrible sweet tooth and cannot live without sweets and chocolate. And he - believe it or not - can walk on the ceiling, such an unusual grandfather! At the same time as Oscar, the Paulsen sisters arrive in Bergen, three rather mischievous ladies who, on the contrary, cannot stand sweets and dream that all the cakes and pastries in the city will become bitter or salty. Why do they need this and will they be able to disrupt the annual city sweets fair, or will someone interfere with their insidious plans? How did this exciting detective story end? Read the book and you will find out.