One of the American indies least likely to appear at Sundance, September Dawn recounts the grim tale of the 1857 Mountain Meadows massacre, wherein the men, women, and children on a California-bound wagon train of Missouri settlers were slaughtered by irate Mormons. Mountain Meadows’ unresolved controversies include the degree to which Joseph Smith’s successor, Brigham Young (Terence Stamp), was involved in planning the atrocity. Although September Dawn suggests that Young lied under oath and let one of his commanders take the fall, it places the blame on a fictional Mormon bishop (steely Jon Voight), who claims to have been informed by a celestial Smith that the gentiles are cursed and soon has his congregation shouting for “blood atonement.” Meanwhile, as the wagon train wends its way through Mormon territory, a certain amount of fraternization transpires, at least among the young people. The bishop’s boy (Trent Ford) locks eyes with a settler girl (Tamara Hope). A pastor’s daughter, she befuddles him by quoting gentle Jesus; he’s the product of a cruel and punitive God whom he hopes to elude by tagging along to California. The schematic script is full of heavy ironies and hackneyed dialogue. And director Chris Cain’s style—let’s call it Americana gravitas—gives September Dawn the ham-fisted lyricism of political ads and pharmaceutical commercials.