In Chapters 4 and 5, we learn more about Mr. Krupp and why George and Harold are scared of him. He is mean, very strict, and always watching the boys to catch them doing something wrong. Mr. Krupp warns George and Harold that if they do not behave, something bad will happen very soon. This makes the boys feel nervous and lets the reader know that a big problem is coming next. Send me a message for your free pdf copy of this book to follow along.