This episode is very hard for me to watch. Scully is taken and there's nothing Mulder can do. But Mulder knows there's something nasty going on and he is determined to find out who is behind it.
He is reluctant to give up the case. He conducts his own investigation but unfortunately Krycek is helping him and he is giving out information to the CSM. In the end, Mulder can't do anything and Scully is taken and Barry arrested and then dead. This is when it became personal for Mulder and Scully. They wanted to stop Mulder from finding the truth: they took Scully away and that kept him busy for a while. Again, this is the first of many excellent arcs with classy perfomances and amazing stories. David Duchovny's performance can't be ignored as he is the center of this episode. We get to see Margaret Scully again and she meets Mulder under terrible circumstances. Poor Mulder, he has all the evidence and it must've been so frustrating for him not able to do anything to save Scully or discover the authors of her abduction. And last, Mulder obviously has developed a different feeling for Scully that has him thinking of her in so many ways.