Disenchantment (2018)

S4E8 Tunguska (1)

Mulder receives a lead regarding possibly perilous paramilitary activities occurring within the U.S. During a sting operation, he is taken aback to learn that his secret informant is none other than Alex Krycek. Doubting Krycek's intentions, Mulder hesitantly pursues the lead. As he digs deeper, he uncovers a far-reaching conspiracy that leads him to a gulag in Tunguska, Russia, where inmates are subjected to experiments involving an alien-derived substance.