Senior homicide detective Frank Spencer bears the scars of many battles with his superior officers and a failed marriage. Dealing with his personal demons, Frank struggles to hold on to the one thing he has left: his career. Assigned to a new case, Frank is teamed up with general investigations detective Mike Estrada. Young and eager, Mike has his own problems trying to navigate the minefield of detective work while keeping his family life from falling apart. The pair soon find themselves following a trail of clues in pursuit of a vicious serial killer. But the demands of working on the case take a toll on the detectives as they confront many obstacles in dealing with family, the department, and even with each other.