The title character of this low-budget drama is a 13-year-old girl living on a trailer park in Washington State; her father, who’s in the armed forces, hasn’t returned from fighting overseas in four years, and her mother (Melanie Lynskey), a nurse, has secretly started dating other men. Sadie doesn’t know how to deal with these developments, and so she sublimates her feelings with increasingly inappropriate behavior. Writer-director Megan Griffiths generates a certain dark fascination in charting the girl’s emotional descent—in fact this verges on becoming a psychological horror film—yet the filmmaker is more interested in crafting an elegy for blue-collar America, touching on such issues as opioid addiction, broken families, and economic stagnation. The movie doesn’t hit as hard as it should since Griffiths strikes such a monotonously grim tone and the performances aren’t very convincing. With Tony Hale and John Gallagher Jr.