Casey is a young boy wandering the world as a spirit . . . but he's not dead, as far as he knows. Stumbling upon the Ghost Circus, a bizarre traveling show filled with phantom performers who entertain other ghosts, Casey meets Creepy Girl, a ghost who cannot move on, and Polterghost, a silent sheet ghost. The three strike up a tentative friendship, and realize that none of them truly fit in at the circus. Sensing a common cause, Casey and Creepy Girl agree to work together to find out why Casey has crossed over to the ghost realm, and what happened in Creepy Girl's past that is holding her back. But as they investigate, they discover that the Ghost Circus itself is not all that it seems, and a bigger mystery is at hand. Will the spectral trio be able to free the souls trapped in the Circus, or will they all go down in the end?