"The door to Ms. Balian's darkened room clicked. From her hiding place, Nicki drew in her breath suddenly. Someone had slipped into the room A dark figure moved quietly through the rows of desks and stood in front of the dresses, waiting . . ." Strange things are happening at Pine Grove Middle School-vandalism, dog-napping, stolen papers, and threatening notes. Is there a connection between the unusual girl and the mysterious mark that keeps appearing...