The new documentary Seadrift opens with a tranquil shot of the bay in the tiny Gulf Coast fishing town that lends the film its title. Frogs jump and a heron preens its feathers as the last of the day’s light falls over calm waters. A resident proudly attests that this sleepy coastal community an hour northeast of Corpus Christi has neither a stoplight nor a fast-food franchise. But then the action jumps to 1979, with a montage of TV news clips that break the peace. “I don’t like them,” a woman snaps at the camera. “They should go back where they come from.” Cut to a 20-something guy in a baseball cap. “Somebody’s gonna take care of those Vietnamese,” he says. “Take care of them?” an interviewer prompts. He doesn’t hesitate: “Kill ’em.”

Before this electrifying, long-overdue film ends, one man is dead, hundreds are scared for their lives and heavily armed Klansmen patrol the bay, burning boats and urging white townspeople to “take back our country.” Forty years later, it’s still not entirely clear how things got that bad. But Seadrift, which was directed by Tim Tsai and screened at festivals in Dallas, Austin and Houston this summer, portrays a community deeply scarred by racism and fear of change. This story is one of the wildest and most disturbing in state history, but because it centers on the plight of refugees in a rural community, most Texans have never heard of it.