"The Know-It-All" is a humorous children's book that tells the adventures of Tina and Theo Theufel. The two siblings live in an old house full of secrets and discoveries. Their parents, who always think they know better, often get in the way, especially when it comes to playing in the attic. However, Tina and Theo are not easily deterred and find a little figure in an old box of books that claims to be visible only to know-it-alls. This figure prompts the siblings to think about know-it-all behavior and the challenges that come with it. With witty illustrations by Astrid Henn and an engaging writing style by Marc-Uwe Kling, this read-aloud book is perfect for all little and big know-it-alls. It encourages reflection while providing plenty of fun and entertainment.