Acclaimed author Patricia Highsmith (Mirren) has no desire to leave her sanctum in Switzerland before she dies. But her solitude is interrupted by Edward (Ehrenreich), a young literary agent, who is sent by her relentless publishing company to convince her to pen one last novel in her wildly popular “Ripley” series. Patricia uses her famously macabre imagination to scare Edward away, but Edward proves resilient. Eventually, she gives in and even takes him on as her writing partner. As the pair collaborates, Edward adopts Patricia’s fiendish perspective and finds that the reality she’s constructing for Ripley is indistinguishable from his own.