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 Martin Landau Kurtzweil Jeffrey DeMunn Bronschweig Tom Braidwood Frohike Blythe Danner Cassidy Terry O'Quinn Michaud Dean Haglund Langly Bruce Harwood Byers Armin Mueller-Stahl Strughold Lucas Black Stevie Cody Newton 3rd Boy Don S. Williams Group Elder George Murdock 2nd Elder Michael Shamus Wiles Black-Haired Man Darrell Davis Primitive #1 Tom Woodruff Jr. Creature #1 Ted King FBI Agent on Roof Steve Rankin Field Agent Gary Grubbs Fire Captain Cooles Steven M. Gagnon Last Agent Out Larry Joshua DC Cop Ian Ruskin Well-Manicured Man's Valet Josh McLaglen Buzz Mihoe 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 Martin Landau Kurtzweil Jeffrey DeMunn Bronschweig Tom Braidwood Frohike Blythe Danner Cassidy Terry O'Quinn Michaud Dean Haglund Langly Bruce Harwood Byers Armin Mueller-Stahl Strughold Lucas Black Stevie Cody Newton 3rd Boy Don S. Williams Group Elder George Murdock 2nd Elder Michael Shamus Wiles Black-Haired Man Darrell Davis Primitive #1 Tom Woodruff Jr. Creature #1 Ted King FBI Agent on Roof Steve Rankin Field Agent Gary Grubbs Fire Captain Cooles Steven M. Gagnon Last Agent Out Larry Joshua DC Cop Scott Alan Smith Technician Ian Ruskin Well-Manicured Man's Valet Michael Krawic 2nd Paramedic Larry Rippenkroeger Towncar Driver Josh McLaglen Buzz Mihoe Randy Hall Windbreakered Agent Vanessa Morley Young Samantha Mulder (archive footage) Jason Beghe FBI Man at Bomb Site (uncredited) Glenne Headly Barmaid