I loved this episode. It was an emotional rollercoaster for characters and viewers. The opening sequence was fantastic. I loved the clips from previous episodes show as viewed by another and Scully's voice over was beautiful. Gillian Anderson did a wonderful job of protraying the extreams of emotion Scully was feeling in this episode - sadness, loneliness, anger, resentment, frustration, compassion the list in endless.
This episode was in my opinion well written and perfectly pitched in the season. I liked the fact that it brought yet another layer to the conspiracy but at the same answered some questions about scully's personal life.
What was lacking in this episode in terms of spooks was certainly made up for in drama.