After a hard breakup with his fiancé, Grace decides to live in a family country house for some time. According to the plot of Voices there, she reunites with her sister, but soon realizes that she is sick with paranoid schizophrenia, like their deceased mother, who committed suicide. And the more Grace plunges into family secrets, the more she doubts her own sanity.
Our heroine slowly ceases to distinguish between the reality and the world of paranoia. But whether she is sick, like her sister and deceased mother remains a question.