“Natchez” captures an unsettling clash between history and memory in a small Mississippi town; a layered mosaic of people contending with the weight of the past in a place where it is always present. Equal parts amusing and disturbing, we journey through an antebellum tourist destination at a crossroads as it grapples with a deeply troubled history that is so thoroughly ingrained in its present, we’re left to wonder if it’s actually past at all.