A series of deaths have started occurring in New York; Some are being found mutilated while others have an equation wÎ"z = Cov (w,z) = ßwzVz carved onto their skin. As police investigate they discover each victim was forced to choose between sacrificing their own life or a loved ones' life. Before long it becomes clear that this perpetrator has suffered just such a similar fate...so now is coping by seeking a way of solving this philosophical enigma, can Captain Maclean and his officers such as Eddie Argo (Stellan Skarsgård) and his new partner Helen Westcott (Melissa George) stop this suspect, because he/she won't not until he/she gets to the end of this equation.