Sendak’s first foray into the world of pop-up books is a brilliant success. After Yorinks sets up the Are You My Mother? theme with a twist, Sendak makes it his own, and Reinhardt adds the surprises as a little Mickey-like boy moves through a haunted house, from monster to monster, looking for his mother. None of the ghouls stands a chance against the mischievous tyke, as he unscrews Frankenstein’s monster’s bolts, pulls down the werewolf’s pants and spins the Mummy in its own wrapping. This last action makes the most effective use of the pop-up possibilities: When the gatefold is opened, the creature actually spins on a dowel pulled by the boy. The combined talent of Sendak, Yorinks and Reinhart offers some of the best art and artistry in the genre: As each page is opened, the spread is filled with multiple pop-ups of everything from a bag of “hands” to a snake poking out of a basket, as well as a side gatefold, also a pop-up, illustrating each monster’s undoing. The text is only one word—“Mommy?”—until she is found in a surprise ending and answers—you guessed it—“B-A-B-Y!” Readers will answer, “AGAIN!” (Pop-up. All ages)