Just when fifth-grader Xander Stone decides to give up his long search for magical creatures, he encounters three Rainbow-Barfing Unicorns, who were banished from the magical world of Pegasia after an encounter with a mysterious object leaking green gas turned them into smelly, zombie-like, rainbow-upchucking creatures--and Xander will need to keep his wits about him if he is to hide the true nature of his new friends from other humans.