When Jessica and her friend Ryan use a double-sided coin they bought at HorrorLand in a coin toss, it transports them back in time to a hostile era where their only chance of survival is to find the prince's missing head.
Twins Jillian and Jackson are worried when they develop strange mental powers, and then an odd scientist from the mysterious and sinister Institute develops an interest in what they can do and starts following them around.
Andy, Sam, Jessica, Meg, Marco, and Ray are trapped by Jonathan Chiller, who expects payment for the rare HorrorLand souvenirs they have taken by playing his deadly game.
Steven, a practical joker, is tricked by his friends into drinking a strange mixture of chemicals that causes him to shrink, and he must make it through his house and the dangers inside to reach his normal size.