From the New Yorker "20 Under 40" author of Atmospheric Disturbances comes a brain-twisting adventure story of a girl named Fred on a quest through a world of fantastical creatures, strange logic, and a powerful prejudice against growing up.

Fred and her math-teacher mom are always on the move, and Fred is getting sick of it. She's about to have yet another birthday in a new place without friends. On the eve of turning thirteen, Fred sees something strange in the living room: her mother, dressed for a party, standing in front of an enormous paper lantern--which she steps into and disappears.

Fred follows her and finds herself in the Land of Impossibility--a loopily illogical place where time is outlawed, words carry dire consequences, and her unlikely allies are a depressed white elephant and a pugnacious mongoose mother of seventeen. With her new friends, Fred sets off in search of her mom, braving dungeons, Insult Fish, Fearsome Ferlings, and a mad Rat Queen. To succeed, the trio must find the solution to an ageless riddle.

Gorgeously illustrated and reminiscent of The Phantom Tollbooth and The Wonderful Wizard of Oz, Rivka Galchen's Rat Rule 79 is an instant classic for curious readers of all ages.