In 2022, New York psychiatrist Dr. Eliza Knight (Julianne Moore) begins treating a patient registered as Case 63 (Oscar Isaac) who claims to be a time-traveler from the year 2062.
Session two. Case 63 delves into the goal of his mission: to save the world. But from what? Or from whom? And how will Dr. Knight help?
Session three. Case 63 describes the lethal virus, patient zero, and his bleak depiction of the future.
Session four. Dr. Knight discovers that, according to Case 63, she is an essential part of his plan to save the world. But, how can she trust a future she doesn't even believe in?
Session five. Case 63 begins to doubt. Dr. Knight begins to believe.
Session six. The polygraph test. Why is the impossible impossible?
Session seven. Dr. Knight decides to drop the case...Case 63.
Session eight. In an unexpected turn, Case 63 is an impostor. And, for now, he has escaped.
Session nine. Intersecting timelines. Dr. Knight surrenders to a plan that science cannot explain. Case 63 has resurfaced to leave a final recording for her.
Final session. In an airport, the meeting of all possibilities and all possible universes. But what happens when the future is not exactly what they expected it to be?