In Birmingham, lead Detective Henry Lucas is working the brutal stabbing of a young mother killed in her own bedroom. With no obvious motive, the investigation hits a wall until Lucas discovers the victim is missing a diamond ring. Meanwhile, the Harris County Homicide squad and lead investigator Sgt. James Dousay are hunting the killer of a man found shot to death in his car. With no witnesses, Dousay hopes the last messages on the victim's phone and the victim's family and friends can lead them to their suspect.