Upheaval comes to the Choctaw Nation of Oklahoma over a proposed Native Theme park. The odd alliance of an Apache and a Sioux promoter attracts the attention of Choctaw officers when a powwow doesn't seem to be the philanthropic fund-raiser it is touted to be. Then a fourteen-year-old Sioux boy is found dead in the Kiamichi Wilderness. The death looks like a drug overdose, but the county investigator finds other, more baffling evidence that draws in the unauthorized involvement of four tribal officers: one Sioux and three Choctaw, including Lieutenant Sam Chitto.
Lawmen are the "thin blue line" that holds back chaos, but each officer struggles with his own internal demons that put adherence to the code of ethics and the vows he took as an officer at risk. The dead boy's grandfather, the Sioux officer, believes he has evidence the death was murder and wants to execute his own brand of justice. Meanwhile, Sam discovers one of the promoters is a five-dollar Indian - a white man posing as native to profit at Native Americans' expense. The imposter is none other than Leon Messina, grandson of old drug lord Victor Messina - the man behind the gangland killing of Sam's father.
Will mistrust, suspicion, and a deep desire for revenge prevent these four lawmen from working together to ensure justice is served?