David Mills (BP) is a police detective who looks into homicide cases. After a transfer he has to work with William Somerset (MF). After their initial differences William decides to take the retirement. But just then a case of a serial killing comes to light. And another.

The killer is a sociopath who justifies killing people as absolution for world's ignorance of the seven deadly sins. Both of them are just one step behind the killer when one day he walks into the police headquarters. Things get personal as Mills' wife Tracy(GP) is pulled into the scene.