Jennifer Garner Sydney Bristow Actor Victor Garber Jack Bristow Actor Ron Rifkin Arvin Sloane Actor Michael Vartan Michael Vaughn Actor Lena Olin Irina Derevko, Laura Bristow Actor Bradley Cooper Will Tippin Actor Merrin Dungey Francie Calfo Actor Carl Lumbly Marcus Dixon Actor Kevin Weisman Marshall Flinkman Actor David Anders Julian Sark Actor Terry O'Quinn F.B.I. Assistant Director Kendall Guest Star Austin Tichenor Dr. Nicholas Guest Star Victor McCay Agent Rudman Guest Star Chris Ellis Agent Chapman Guest Star Peggy Goss Attending Nurse Guest Star Reamy Hall Nurse 2 Guest Star Petra Wright Alice Williams Guest Star Don Took Agent Grey Guest Star Jim Hanna Claus Richter Guest Star Michelle Arthur Abigail Guest Star Ivan Borodin Lab Technician Guest Star Stephen Davies Sark Associate Guest Star Mak Takano Ryokan Guard Guest Star Stephen Mendillo Henry Fields Guest Star Joel Guggenheim Agent on Call Guest Star J.J. Abrams Executive Producer John Eisendrath Executive Producer, Writer Ken Olin Executive Producer Dan Attias Director