Twelve-year-old Lonnie is finally feeling at home with his foster family. But because he's living apart from his little sister, Lili, he decides it's his job to be the 'rememberer' and write down everything that happens while they're growing up. Lonnie's reflections in his letters to Lili are bittersweet. He's happy that they both have good foster families, but while his new family brings him joy, it also brings new worries.