Abed’s rhyming prowess propels this sprightly picture book that follows two siblings jointly composing an adventure. Employing simple couplets, a tan-skinned youth sets the scene: “The other day I wrote this book./ You won’t believe how long it took.” Enter brown-skinned sis, who disrupts the lines with jarring concluding phrases (“She ruined every rhyming verse,/ so now my story sounds much—// MORE MAGNIFICENT!”). The narrator persists in trying to craft the conventional tale of a knight’s daring search for treasure, but plot twists abound as the sister’s alternatives insert a rocket, dancing pirates, and a fire-breathing armadillo. Just as the conceit seems clear, the suggestions become workable rhymes, and the siblings at last find a collaborative scheme. Aly’s energetic digital renderings lean on graphics and sketched overlays to capture the duo’s narrative exploits. Ages 3–7. (Mar.)