A series of gruesome murders leads an Indianapolis cop & a university professor to the doorstep of Cedar Point P.I., Chase Dagger. They have a theory behind the killings. Sergeant Marty Flynn has been tracking the suspect since March 13, 1998. Professor William Sherlock has been researching the killer's family for far longer. They believe the killings only occur prior to & during a full moon when it falls on a Friday the 13th. The professor believes the evil is passed on from generation to generation. Dagger's suspicion is aroused, feeling the professor knows far too much about the suspect & the murders. But when the 2 men mention shape-shifters, Dagger is forced to reexamine their theory. After all, Sara, his partner, is a shape-shifter. Yet, Sara has never known any other shape-shifters, & doesnt's believe something this evil could exist...that is until IT starts communication with her.