Mulder and Scully, reunited at last, head for an active volcano under a geological study and find a deadly life form that can survive in the searing heat of the crater and is killing the scientists to avoid being discovered.
Quest roles:
David Lewis(Young Agent), Bradley Whitford(Daniel Trepkos), David Kaye(Doctor (uncredited)), Leland Orser(Jason Ludwig), Hiro Kanagawa(Peter Tanaka), Shawnee Smith(Jessie O'Neil), Tuck Milligan(Dr. Adam Pierce)