The chances of redemption look pretty slim for student Rhoda (Marling) after she drunkenly rams a car after a night out, killing a pregnant mother, her young son and putting the father into a coma.
Thrown into the slammer for four years, she emerges as a forlorn 21-year-old, takes a mentally void job as a school cleaner while seeking sanctuary in her de-cluttered attic bedroom.
On the night of the accident it was announced that a planet - the exact replica of Earth - had swung by from the solar system and had become a permanent fixture in the sky during Rhoda's years of incarceration.
Tentatively making inquiries, she discovers that the victim of her crash - composer John Burroughs (Mapother) - is now out of hospital and living the lonely life of a middle-aged widower in an isolated clapboard house.
She approaches - with the intention of making a guilt-purging apology - but loses her nerve and finds herself deceiving Burroughs with a tall tale that she's a contract cleaner.
Slowly, John emerges from his deep well of grief and strikes up a easy-does-it relationship with Rhoda, completely ignorant that it was her actions that destroyed his life.
At the same time - and this is straining things a bit - Rhoda discovers she's won a competition for a seat on a spacecraft voyage to the new planet, a trip that could result - is research if to be believed - in her meeting her own doppelganger.
This is a bizarre collision between low-budget sci-fi and the mumblecore aesthetic, a yearning romance that just about stays in orbit thanks to strong performances from Marling and Mapother.
Hugely ambitious, it's successful enough to be worthwhile and the emotionally-satisfying pay-off is, despite the potential to be utterly risible, rather charming.