Harriet wants to become an author so she keeps a secret notebook about her classmates. But when she misplaces her notebook and it falls into the wrong hands, Harriet knows she is going to have a lot of explaining to do. Kate says: "Not too long ago, I remembered that I read and loved Harriet the Spy [as a kid], and so I went back to it as the adult me, with some trepidation. ... And it's even better and more subversive than I remembered. It's basically a primer on how to be a writer."