It is common knowledge that big sisters are the best keepers of their brothers. But when Nana finds her brother's bed empty one evening, in a fit of insomnia, she shows that sisterly love is so strong that she will easily turn the room upside down in search of him, confront spiders, and even put together the most difficult puzzle. Just as she will explain to him what the ceiling or trance is or how the heart can race, Nana will take her brother - and with him, us - on an exciting night adventure through the corridor through the bathroom, and the living room all the way to the room. And that as long as the parents sleep, and restless thoughts fly far away, even through the window, endlessly. With a lot of tenderness (but also some sisterly jokes) she will reveal to the boy - and for us too - the most important truth that we all sometimes forget: that the world needs him the most just as he is.