Telling about the heroine Grace Sachs (Nicole Kidman) living the ideal life in her mind: Grace is a successful psychotherapist, has an excellent doctor husband and a son who studies in an elite private school, and she is preparing to publish a gender issue The book "You Should Have Known" mainly reprimands women for not observing their instincts and failing to see the meaning presented by their male partners.
However, a few weeks before publication, when a fatal incident involved her husband who suddenly disappeared, Grace discovered that there was a huge crack in her life, and there were early warning signs in the past, but she did not follow her instincts. But after the matter was upset, the hostess gave up her current life for her son.
