Emily and Martin Taylor are a beautiful, wealthy couple living the good life, with a mansion, a sailboat and every luxury money can buy-until Martin is sent to prison for insider trading. For four years, Emily waits for him in a tiny apartment in upper Manhattan, but his release is just as devastating as his incarceration, and Emily sinks into a deep depression. After a failed suicide attempt, psychiatrist Jonathan Banks is called in to consult on Emily's case. Desperate not to be hospitalized, Emily agrees to a regimen of therapy and antidepressants. When Emily's symptoms don't improve, Banks prescribes a new medication that quiets her demons, but the side effects of the drug have chilling consequences.