As Little Blue Truck drives to a Halloween party, readers can lift flaps to find out who is hiding beneath the costumed figures he encounters: “Who’s this queen/ with a golden crown/ and sparkling jewels/ and a velvet gown?/ Under the mask who do you see? ‘Moo!’ says the cow./ ‘It’s me! It’s me!’ ” McElmurry’s richly rendered scenes and the animals’ elegant costumes conjure up a sense of nostalgia that befits Little Blue Truck’s own vintage looks. And after delivering all of the animals to the party, Little Blue Truck gets a chance to dress up himself, using a large white sheet to turn into a ghost. Up to age 3.