In the library, you saw a kid you don't really know, from another class, knock a stack of books off a shelf and tear a couple of pages while shoving them back. They walked off fast. A minute later, the librarian finds the mess and blames the only kid nearby — a quiet boy called Sam, who was just reading and had nothing to do with it. Sam is trying to explain and getting nowhere. The librarian's annoyed and not listening. You know exactly who did it. The real kid is from a different class, so it's not "your business," and speaking up means getting involved in something with strangers. But Sam's about to be punished for something you watched someone else do.