Fifth-graders Rachel Maurer, Trevor Klarer and Owen Klemm look over a note they plan to leave in the book “My Secret Unicorn” at Northside Elementary School June 7, the last day of school. They had originally checked out the book by Linda Chapman because they thought it had a corny title and then enjoyed putting it in different bins in the library, such as the Roald Dahl section and the animal nonfiction section. The note was to future students telling about their joke.