After successfully capturing Rose, John and Cotton plan to extract information on the Grand Rite from her during the planetary alignment with Saturn. Mary assists Mercy in becoming a witch and initiates her into the hive.
Mercy wants to rule Salem alone and uses Hathorne to do so. Anne is pregnant and being tortured by the devil. Cotton therefore returns to save and protect his unborn child and Anne.
Mulder searches for Doggett and his new partner after they are trapped with a deadly reptilian monster.
Scully and Doggett investigate several killings involving a terrifying bat-like creature.