Ep 1. Herrenvolk (2)

In season 4 episode 1 of The X-Files titled "Herrenvolk (2)", Mulder and Scully continue their investigation into what appears to be an alien conspiracy within the United States government. The episode picks up from where the previous season finale left off, with Mulder and Scully stranded in an abandoned missile silo and trying to make their way out while fighting off a group of alien bounty hunters.

As the episode progresses, Mulder and Scully discover a shocking truth about the conspiracy they've been investigating. They learn that a group of powerful government officials have been working with a race of alien colonizers who have been using human beings as hosts for their offspring. The alien race, the "Purity Control", is intent on creating a perfect breed of human-alien hybrids.

Meanwhile, Mulder's sister, who has been abducted by the aliens since she was a child, finally makes a return in this episode. Her appearance is a turning point in the series, as her story arc has been a central theme since the beginning of the show. As Mulder attempts to connect with his sister again, Scully is also dealing with her own personal demons, as her cancer diagnosis in the previous season's storyline takes a toll on her.

The episode is full of tense moments as Mulder and Scully navigate their way through the conspiracy. The series also introduces the character of Marita Covarrubias, an informant who becomes involved in the investigation. Her appearance adds intrigue to the series as she has her own motivations and agendas.

As with most X-Files episodes, "Herrenvolk (2)" also has a twist ending that will keep viewers talking and guessing about what will happen next. Overall, this episode is a thrilling beginning to season 4 and sets the tone for the rest of the season as Mulder and Scully navigate a complex conspiracy involving aliens, government officials, and personal morality.