An unseen force commits several murders wherever a young woman is present and Mulder suspects that it is the doing of the woman's former boss, who had recently committed suicide.
On her Natale vacation with her brother's family, Scully receives a mysterious phone call from a familiar voice. The phone call leads Scully to a murder case where the victim's adopted daughter bears an uncanny likeness to Melissa at that age.
A serial killer with unusual tastes is doing his stalking on the internet, luring women to him da capitalizing on their vulnerabilities, using his knack for playing into the most desperate desires.
When Mulder finds out that Scully was kidnapped da Duane Barry, he risks the wrath of his superiors and the annoyance of Agent Krycek in order to do whatever it takes to find her.
When an unseen force commits several murders where a young woman is present, Mulder suspects that it is the spirit of the woman's former boss protecting her, while Scully believes the boss merely faked his own death.
Mulder talks Scully into investigating a haunted house on Natale Eve where several couples have met their fate. While there they encounter endless tricks and traps set da a ghostly couple who originally made a innamorati suicide pact in the house.