David Duchovny
Agent Fox Mulder
Gillian Anderson
Agent Dana Scully
Mitch Pileggi
Assistant Director Walter Skinner
William B. Davis
The Cigarette-Smoking Man
John Neville
The Well-Manicured Man
Jeffrey DeMunn
Bronschweig
Armin Mueller-Stahl
Strughold
Christopher Fennell
2nd Boy
Don S. Williams
Group Elder
Michael Shamus Wiles
Black-Haired Man
Darrell Davis
Primitive #1
Carrick O'Quinn
Primitive #2
Tom Woodruff Jr.
Creature #1
Ted King
FBI Agent on Roof
Gary Grubbs
Fire Captain Cooles
Steven M. Gagnon
Last Agent Out
Gunther Jenson
Security Guard
Scott Alan Smith
Technician
Ian Ruskin
Well-Manicured Man's Valet
Paul Welterlen
Control Room Operator
Joel Traywick
Young Naval Guard
Milton Johns
British Valet
Michael Krawic
2nd Paramedic
Larry Rippenkroeger
Towncar Driver
Randy Hall
Windbreakered Agent
Vanessa Morley
Young Samantha Mulder (archive footage)
Jason Beghe
FBI Man at Bomb Site (uncredited)
Glenne Headly
Barmaid (uncredited)