What exactly happens in your brain while you sleep? A whole lot!  A whole lot! When Malu goes to sleep, Hippo and Campus not only sort out all the new impressions that Malu has collected during the day, but they even help her find her lost teddy bear! This makes Malu very happy when she wakes up. In a playful and easily understandable style, Anna Russelmann explains why it is so important for children to get enough sleep. The illustrations in watercolor and chalk capture the dreamy atmosphere of the night.