Warning: Full spoilers for the episode below. For its 100th episode, just four episodes out from the series finale, Person of Interest unleashed one of its most intense, heartbreaking, and haunting installments to date. An action-packed, crushing blow to help lead us into what's mostly likely going to be a very dark endgame for our heroes. For seasons now, we've known - and have been told by our beloved characters - that the war against Samaritan was to be a costly one and that any victory would be a pyrrhic one.