Two children stuck inside on a rainy day use their imaginations to stave off boredom.Having exhausted their usual indoor activities, small gal pals Kiki and Anna stare out the wet window despondently. But then, in a stroke of inspiration, Kiki invents a special game: "We could play the Think-Ups!" The rules are simple: Think of something and it will appear. Anna is skeptical at first, but soon the girls are conjuring up bunnies, octopuses, koalas, and even a moose! They initially revel in their wild animal apparitions until the mischievous menagerie takes over the house, making a mess in the kitchen and causing general chaos. Luckily, the children think up a way to restore order just as the sun comes out…but their imaginary troubles aren't over yet! Alexander's exuberant text lends itself perfectly to reading aloud, with playful verbal flourishes such as "wriggling, giggling octopuses." The digital illustrations, executed in a mostly pastel palette, have a hand-drawn feel and effectively convey the hilarity, charm, and unbridled energy of young children's play. Kiki and Anna's rapidly shifting emotional extremes are dead-on and offer additional points for discussion. Occasional wordless spreads give readers a chance to take a breath during the make-believe mayhem and soak in all the details. Attentive readers will notice clues peppered throughout that foreshadow some of the hijinks. All characters are light-skinned. (This book was reviewed digitally.)A deftly executed homage to the power children possess to imagine away a dreary day. (Picture book. 4-7)

PreS-Gr 1 While waiting at home for the rain to end, dark-haired Anna and blond Kiki get tired of their usual indoor games, such as hide-and-seek and snakes and ladders. To keep boredom at bay, Kiki suggests they play "The Think-Ups." "All you have to do is think up a Think-Up and it will appear!" With this simple rule, the girls take turns summoning imaginary animals. Bunnies, koalas, octopuses, and even a giant moose appear and entertain the children while wreaking humorous havoc around the house. When the chaos crescendos, Kiki conveniently thinks. "All Gone," and peace is seemingly restored, the sun comes out, and the girls head outside with the promise of more high jinks from a "you-can't-catch-me-lion." Alexander's sweetly cartoonish illustrations are very funny, though neither they nor the text resolves the ambiguity of whether the entire mess was real or imaginary, nor is there parental presence of any kind. VERDICT Not an essential purchase, this delightful and imaginative romp will have readers giggling and wishing for Think-Ups of their own. Yelena Voysey, formerly at Pickering Educational Lib., Boston Univ.