Former crime-scene investigator Megan O'Ryan helped convict the St. Patrick's Strangler, who killed Megan's sister. Now she's trying to heal in a small Wisconsin town. But a copycat killer is at work in Crystal Lake, and Sheriff Luke Torretti needs Megan's help... on the case and at home, where the widower's troubled teenage son has become a suspect. The boy claims he's innocent - and Megan believes him. Because the more she and Luke investigate, the more Megan becomes convinced that her own past has brought the killer to Crystal Lake. And without Luke's help, the next victim will be her.