The ingenuous little girl from the Caldecott Medal–winning The Hello, Goodbye Window (2005) is back, exploring the split personality that causes her loving grandparents to give her two very different names. She explains, “Poppy doesn’t like Sourpuss too much. Neither does Nanna. I mean they like her because she’s me, but not so much. Do you know what I mean?” Anyone who’s ever spent time with a young child will know exactly what she means, as will children themselves. Once again, Juster nails the inner life of a child, capturing perfectly the mercurial mood swings that can turn adorable into awful in the blink of an eye—and capturing also the child’s own bewilderment at the process. Raschka’s childlike, gorgeously smeary, textured images employ ever-so-subtle shifts in color and line—and not-so-subtle scowls—to chart the curly-haired moppet’s transitions from Sourpuss to Sweetie Pie and back, one fabulous double-page spread that fairly bristles with crankiness acting as a set of body-language studies in truculence. Readers will be as happy as Nanna and Poppy to welcome both of them back. (Picture book. 3-7)