Writer-director Trey Edward Shults (Krisha) delivers the most self-important American horror film since A Girl Walks Home Alone at Night. Heavy on mood but light on ideas, this is the sort of movie that equates ambiguity and draggy pacing with seriousness. After a plague wipes out much of the earth's human population, a family living in a secluded woodland home hoard their resources and arm themselves to the teeth. They take in a second family, and the characters develop a sense of camaraderie, but the interpersonal bonds are tenuous. Shults might have had something on his mind about Americans' propensity for individualism and violence, but any viable theme is overwhelmed by the empty style. With Joel Edgerton and Carmen Ejogo.