A party in itself, full of pop-up and pull-tab surprises. The celebration is all dreamed up by a friend to counter pessimistic mouse Barbara's view of her coming birthday. And it's a glorious occasion that he envisions, with 813 animal guests, a room full of presents (you can lift the flaps to open some), balloons that rise and a firecracker-favor that snaps, pop-up ice cream and cake, and a baton-waving conductor to lead the Happy Birthday chorus. ""'Then my birthday is over?' 'No, no--that's when the parade starts'""--and we see a splendid strip of fold-out pages, followed by a multiple explosion of fireworks. But this is not one of those staggering spectacles designed to impress; Stevenson aims more to delight than to astonish, and he goes at it with an air of playful innocence that's irresistible.