Following the deaths of their parents, sisters Lilly and Victoria are taken in by a spectral motherly figure, who they call "Mama." After years of living in an abandoned cabin with Mama, the siblings are found by their Uncle Lucas (Nikolaj Coster-Waldau) and his girlfriend, Annabel (Jessica Chastain). The couple takes the children in, not knowing about Mama, and discovers that the girls' phantom protector isn't ready to let them go.