What is the book if he had been with me about?

"If He Had Been With Me" is a young adult novel written by Laura Nowlin. The story follows the protagonist, Autumn, as she navigates high school and growing up without her childhood best friend, Finny, by her side. Throughout the book, Autumn reflects on their relationship and wonders how things would have been different if Finny had stayed with her. The novel explores themes of friendship, love, loss, and self-discovery. It is a poignant and emotional read that has been praised for its heartfelt storytelling and relatable characters.