Thorkild Christensen stares down at his murdered wife, Karen, and realises he knows almost nothing about her. How did she fill her days? Where did she disappear to every Thursday? Lead investigator Detective Thea Krogh is determined to find out. And then a second woman is shot dead. There is seemingly nothing to link the two victims, and the police move on, desperate for a lead. But someone out there has a deadly secret. And as events begin to play out - masterminded by a strange and bewitching figure - all of their worlds are about to come crashing down . . .