Ruth, a 30-year-old woman who has been estranged from her family for some time, returns home when her mother dies under strange circumstances. There, she is reunited with her father, Martín, who since retiring seems to have become a grumpy, aggressive man obsessed with a sinister conspiracy theory. The relationship between the two of them is so tense, and his behavior so erratic, that Ruth begins to suspect Martín might be responsible for her mother's death. Is it possible she's sharing a roof with a murderer?