In Memphis, Lt. Toney Armstrong and his team respond to Memphis’s worst mass murder in more than 15 years, where they find four adults and two children dead. Armstrong’s entire team is called to action as they scramble for leads, while the local media follows their every move. When investigators learn that the killings may have been committed by a “Blackout” squad–a gang-ordered directive to wipe out an entire family–they need to find the killers before they strike again.