 The show centers on FBI special agents Fox Mulder ( David Duchovny ) and Dana Scully ( Gillian Anderson ) who work on cases linked to the paranormal , called X @-@ Files . Mulder is a believer in the paranormal , while the skeptical Scully has been assigned to debunk his work . In the episode , Mulder and Scully believe that a serial killer from the 1940s passed his genetic trait of violence to his grandchild after a detective , BJ Morrow ( Deborah Strang ) mysteriously uncovers the remains of an FBI agent who disappeared almost fifty years before while investigating a modern @-@ day murder case similar to the older cold case . 
