Watch Person of Interest Season 4 Episode 17 Online right here via TV Fanatic. A psychologist's number comes up, and Reese and Finch learn that he is setting up the people who harmed his patients. But the big job is centered on the psychologist's dead wife and him exacting revenge. Of course, some Finch flashbacks and Reese with his therapist reveal the POI team learning to deal with loss. And there's a surprise twist at the end!