Everyone at Sweet Valley Middle School has always said that the Mercandy mansion is haunted. Strange lights flicker in the windows at night, and no one ever sees the owners come and go. So when Nora Mercandy moves into the run-down house, rumors spread fast. Jessica Wakefield and her friends are convinced that Nora is a witch.
But Elizabeth, Jessica's identical twin, is certain that Nora is just an ordinary girl. She's determined to stick up for her new friend. She'll get to the bottom of the mystery of the Mercandy mansion - even if it might mean losing her sister's friendship!

Elizabeth made her way toward Jessica. "What have you done to Nora now? she demanded.
"What are you blaming me for?" Jessica asked.
"She's just a crazy witch," Lila explained to everyone. "Everybody knows the Mercanys are weird. Let her go to the haunted house, where she belongs."
Elizabeth hesitated for a moment. She didn't believe there was any truth to the rumors about the Mercandys, and now she had to help out her friend. She turned on her heel and ran out the front door after Nora.
Jessica started after her sister.
"Let her go," Lila said. "Let's get back to the party."
But who knew what could happen to Elizabeth if she went near the Mercandy mansion on Halloween night!

Will Elizabeth lose her best friend to the Unicorns? Choosing Sides