Detective Casey Shraeger has just been transferred to the NYPD's Homicide unit from Vice and is instantly thrown into a setting of bullets and bodies. As she begins her new assignment, Casey finds that the force is full of secrets, which serves her well, since she's keeping a few of her own. But her first case is not an easy one, as she's assigned to investigate the death of one of the department's own, the former partner of Detective Jason Walsh, who is now her new partner.

As the duo seeks out the cop killer, the secrets and eccentricities of the rest of the department begin to emerge.