The irascible A. J. Fikry, owner of Island Books, has already lost his wife. Now his most prized possession, a rare book, has been stolen from right under his nose. One night upon closing, he discovers a toddler in his children's section with a note from her mother saying she can no longer raise her. It doesn't take long for the locals to notice the transformation of both bookstore and owner, especially to the lovely yet eccentric sales rep, Amelia Loman.