Rosalinda tries on the new red velvet dress her grandmother just finished making. When she twirls in front of the large standing mirror and comes to a stop, she does not see herself. The mirror goes dark, and she finds herself standing in some other girl's bedroom. A boy about her age bursts through the door, stops, and demands to know who she is and where his cousin Rose is. Rosalinda tells him she has no idea how she got there and all she wants to do is get back home.The boy introduces himself as Trace, and they decide to work together to figure things out. Once Trace introduces Rosalinda to Rose's grandmother Lilly, it becomes clear that the woman is a strong but good witch and that magic must have been involved in Rosalinda's travel through the mirror. Trace reveals that Rose had been secretly nosing around in Grandma Lilly's library for magic books and stole some of them. He suspects she was experimenting with some spells.To figure out which spell Rose might have tried that made her disappear and brought Rosalinda in her place, Trace and his new friend explored Grandma Lilly's library-the basement packed with furniture, boxes, and a mysterious trunk, the attic full of clothes and other junk, and finally the lighthouse where Rose hung out.Along the way, Trace and Rosalina encounter an evil witch named Marless, along with several monstrous beasts she uses against them. The pair are helped by Hunter, a friendly warlock. In a cave below the lighthouse, Rosalinda and her allies discover that two innocent characters are trapped in cages suspended from the ceiling, along with frightful creatures also cooped up in the same way. Marless appears with a small army of minions and releases the caged savages to defeat Rosalinda, Trace, Hunter, and Grandma Lilly.Brute force and clever spells clash in a violent struggle to triumph over the opponents. But how will this end? Will Rosalinda and her friends ever find the spell that takes her back where she belongs?
