Guest Stars William B. Davis as Cigarette-Smoking Man Annabeth Gish as Special Agent Monica Reyes James Pickens, Jr. as Deputy Director Alvin Kersh Joel McHale as Tad O'Malley Barbara Hershey as Erika Price Ben Cotton as Mr. Paulsen Madeleine Arthur as Sarah Arthur Sarah Jeffery as Brianna Stapleton Zak Santiago as Mr. Green Alan C. Peterson as Mr. Y Miles Robbins as Jackson Van de Kamp / William Co Starring Keith Arbuthnot as Ghouli JP Finn as Watching Man West Duchovny as Maddy Mark Acheson as Trucker Thomas Nicholson as BDU Soldier Henry Mah as Night Manager Gerry Rousseau as Homeless Man Austin Dunn as William (15 Years) Rogan Christopher as BDU Team Leader Chase Nicholson as William (11 Years) Jodi Pongratz as Female Attendant Tanya Niobe Martinez as Homeless Woman Bentley Hixson as William (5 Years) Cole Lindsay as Jared Marriott