Piper and her little brother Otto, who is on the autism spectrum, are excited to attend a birthday party for their friend Ruthie. In kid-friendly language, Piper explains the accommodations Otto and Ruthie, who is also autistic, need in order to feel safe and secure in a stimulating new environment, such as wearing headphones to keep distracting noises muffled. The book provides explanations for Otto's differences in easy-to-understand language and highlights that Otto desires fun, comfort, and love-just like his peers.