The story centers on a young woman named Rhoda Williams (played by Brit Marling), who is involved in a tragic accident that kills a family, including their young child. Rhoda’s own life spirals into turmoil as she grapples with guilt and the consequences of her actions. Meanwhile, a mysterious planet—an identical Earth—appears in the sky, sparking curiosity and existential reflections about alternate realities.

Rhoda eventually seeks out the family she wronged and begins to form an unlikely bond with the surviving father, John Burroughs (played by William Mapother). As their relationship deepens, the appearance of the parallel Earth becomes a metaphor for the possibility of alternate choices and redemption.