The kids of the Cardboard Kingdom are back-and they have new rivals.It's winter break, and the suburban neighborhood kids are ready to play! Continuing their massive, complex pretend world, they're building their confidence, working out interpersonal dramas, and having a blast. While the first few chapters work as stand-alone stories, the rest quickly build up to a bigger plot: Kids from the Parkside neighborhood have seen how much fun the Cardboard Kingdom is, and they want in. Unfortunately, this situation quickly spirals into competition and conflict as new alliances form and others are tested. Only through communication and collaboration can the different sides create peace. Themes of familial expectations, respecting differences, and teamwork are throughlines: "What if we could show everybody…that we're even more powerful together?" While seeing new characters and dynamics is refreshing, these elements may cause difficulty in tracking the large ensemble cast, most of whom have two identities. Still, Sell's art moves seamlessly between the imagined world of the kids' alter egos and their real-life pretend play, giving each time to shine. As before, the multiple contributors' chapters are seamlessly woven together with Sell's art and overarching vision, mirroring the experiences of the characters. Neurodivergence, queerness, racial and ethnic identities, and socioeconomic status are often implied rather than stated directly. This volume will be best appreciated by those familiar with the earlier books.A fun and thought-provoking series entry. (maps, note to readers, author bios, deleted scene, character designs, photos) (Graphic fiction. 8-12)