Karla and her family are especially good at one thing: making a racket. Karla finds a cello in the attic, as well as a stone lion, guarding a rusty door, who shows her the world of silence and gentle notes. 

Most of all, the moffels like to sleep all day long. Only after midnight, when people are dreaming, do the moffels come out.
They clamber over roofs, wander through empty streets, pass by the bakery and the school, end up at the department store and the zoo, but they can’t find what they’re looking for: a hooman, as the moffels call humans. After all, night is when humans are asleep . . .