It begins as an assignment for English class: Write a letter to a dead person. Laurel chooses Kurt Cobain because her sister, May, loved him. And he died young, just like May did. Soon, Laurel has a notebook full of letters to people like Janis Joplin, Amy Winehouse, Amelia Earhart, Heath Ledger, and more--though she never gives a single one of them to her teacher. She writes about starting hi…