One Halloween night in the town of Hallowed Hills, Logan's sister, Kaitlyn was born... and immediately tried to eat him! At least, that was what Logan believed. As time goes by, Logan keeps his distance from his baby sister. Then one day when Kaitlyn is three years old, she tries to eat his best friend, Joe! From that point on, Logan knows there is something very different about his sister, especially her odd appetite. Unable to convince his parents of her "condition," Logan takes it upon himself to watch over Kaitlyn and make sure she stays out of trouble. As Kaitlyn gets older, Logan finds it harder and harder to keep an eye on her and keep her appetite at bay. The whole town soon becomes aware of her peculiar actions. When some local kids go missing, many think that Kaitlyn may be involved. Now, Logan is about to discover how scary life can truly be having a little sister who's a zombie!