In-jokey science fiction yarn from the author of Callahan's Key (2000), etc. The Dreamworld theme park offers wholesome, appealing entertainment: rides, fireworks, a Heinlein area, Strawberry Fields, Mike Callahan and friends, Master Li and Number Ten Ox, etc. Fleeing a horrible existence, young Mike goes behind the scenes determined to become invisible and live there forever. He soon runs into Annie, a supersmart midget who's lived invisibly in Dreamworld since it opened; she helps out in all sorts of ways and is known to awed maintenance workers as the Mother Elf. Many of Dreamworld's employees are midgets or dwarfs, actors, characters, or ideal for operating in tiny spaces. Annie takes a shine to Mike's quick wits and obvious love of Dreamworld; she shows him how to survive, open doors, and tap into the computer network. Alonzo Haines, however, jealous owner of the rival, violence-ridden Thrillworld, schemes to destroy Dreamworld; he's hired dangerous thug Randall Conway to probe for weaknesses. Conway reports that, somehow, more worker dwarfs come out of Dreamworld than go in. Independently, Annie's just observed the same thing. As Annie and Mike investigate, Conway becomes aware of them. They discover what the intruders are, which makes it doubly important to prevent Conway grabbing one. But can Annie and Mike deal with the ruthless Conway as well as unravel the mystery of the uninvited guests?
Fun in a knowing, rather sophomoric way; should keep most readers engaged and guessing.