The team investigate a mass murder at an internet security company, while Prentiss must complete recertification training under Morgan's supervision.
The CSI team suspects an entire family has been murdered, but cannot prove it without finding the victims' bodies.
Convinced he will be sent to jail, Hal imparts fatherly advice and confesses to Malcolm about his poor work ethic.
Jane and Maura investigate what seems to be a modern-day witch hunt; Frankie's ex-girlfriend comes back, and Jane makes her feelings known about the situation.
Mulder uncovers the government's secret testing of alien DNA on humans.