This is not a book. It's a laptop — open it and the spine becomes the hinge. It's a tent, a toolbox, a monster with its mouth open wide (Niko's favorite), a pair of hands to clap together at the end. Jean Jullien, the French graphic designer whose work appears in the New York Times and the New Yorker, built each spread around the book's own physical shape so that reading it becomes inseparable from playing with it. The first time I saw two five-year-olds banging away on the computer keys and whacking tennis balls across the net, I was genuinely surprised and delighted. It is, as Jullien himself says, a toy with many pages.