Watch Alias Season 4 Episode 20: The Descent Online

	IMDB Rating: 7.9/10 from 190 votes
	Release: 2005 / Alias / Season 4 / Episode 20
	Genre: Action \| Drama \| Mystery
	Director: Jeffrey Bell
	Stars: Jennifer Garner, Ron Rifkin, Michael Vartan
	Synopsis: After a tactical group infiltrates the DSR and steals all the Rambaldi artifacts, CIA director Hayden Chase discovers that the alarms at the DSR were disabled from Nadia's computer, allowing the raid to happen. Mrs. Chase shows up at the apartment to question her. Soon Sloane and Jack arrive and suspect that Sophia, who had access to the computer while she was living with Sydney and Nadia, is in fact Elena Derevko. They follow her trail to a dead Rambaldi follower, a stunning betrayal, and a presumed dead family member when in a surprising twist, Sydney and Naida learn that Irina Derevko is in fact alive and that it was a Helix double of Irina that Jack assassinated in Moscow two years earlier.