When she gets out of prison for vehicular manslaughter, a young woman (Brit Marling) goes to work cleaning house for—and soon becomes the lover of—the man (William Mapother) whose wife and son she killed (he was in a coma all through her trial and doesn’t know who she is). Meanwhile, another planet identical to Earth appears overnight, close enough to loom huge in the sky day and night and evidently with an identical population. Director Mike Cahill isn’t happy with one ridiculous premise; he has to have two. The script is credited to both Cahill and Marling, meaning perhaps that she was allowed to ad-lib her mopey, banal dialogue. A big hit at Sundance (quelle surprise!), the movie is a grungy, lugubrious art-house Plan 9 From Outer Space with mumbling, tongue-tied delusions of allegorical grandeur.