By far the strongest and most important Mythology until now. And probably one of the best Mythologies of the entire show. It's not as vague or slow moving as previous episodes, and thank the lords of Kobol that it wasn't filled with tons of cheesy lines including the word 'truth'.
Duane Barry was an extraordinary character and his abduction scenes featured some of the best scenes of the series. They were very well done and some of them borderline creepy. The hostage scenes were also superbly done, the hostages all did their part. and the scenes between Mulder and Duane were also superbly done.
Scully's character, although not that important in this episode had some really nifty scenes. She and the tracking chip, and the cliff-hanger with Duane attacking her at her home. Yeah, if you didn't care for the Mythology yet you would after this episode.
FIVE stars, easily. My second favorite episode yet.