Set in the fictional town of Orson, Mississippi, Mississippi Blue follows the investigation of Mary-Lee Hastings, the six-year-old daughter of upstanding citizen and preacher, Mark Hastings, who disappears without a trace one hot summer night in June, 1969. Detective DuBois and newly appointed Detective Carolina Waterson answer the call as the town’s secrets start coming out—and decades of fear, hatred, racism, and violence are revealed. All the while, The Thing—an unspeakable beast not of this world—waits and watches. Enter Seth Barton, a man with a very special ability. An ability that lets him see a different side of Orson, a side he calls The Blue, only reachable by plunging himself into the deep waters of the Mississippi. He finds an unlikely partner in Detective Waterson, and together they race to defeat The Thing and rescue Mary-Lee before the town comes crumbling down around them.