Scully and Mulder look for answers to a bizarre series of murders in which all the victims died during sex. Their investigations lead them to an Amish-type community in Massachusetts.
An old Oxford University classmate and girlfriend of Mulder's asks for his help in investigating an international case in which several British dignitaries were executed.
After the body of a decapitated EMT disappears from the morgue and an identical man starts work at the same hospital, Mulder believes that the man has the ability to regrow parts of his body, including his head.
After Mulder chases down and kills a young man whom he believes to be a vampire, Scully realizes that his fangs are fake. Faced with a lawsuit from the family of the man, they recount each of their sides to the story leading up to the event.
A detective mysteriously uncovers the remains of an FBI agent who disappeared in the 40s, Mulder and Scully believe that the original killer had passed his genetic trait of violence.
An old Oxford girlfriend of Mulder's asks for his help in an international case concerning the unexplainable execution of several British dignitaries and they encounter an assassin who can produce fire from his bare hands.