Jay Gatsby x Nick Carraway

This is "The Great Gatsby" Chapter 10... narrated by Nick (and the author) who is now the new Gatsby. Although, he doesn't have the same taste of lasciviousness and Gatsby did. He lives a quiet and quaint life. None of the exciting and chaotic parties Gatsby hosted. But what happens when Nick goes to visit Gatsby and his grave is disturbed? Who would do that? What would their reason be? And how does Nick handle it?