Episode 86 of "Alias"
s04e20 The descent
Title: The descent
Original Air Date: 05/18/2005 on ABC
Director: Jeffery Bell
Writer: Jeffery Bell
Guest Stars: Angela Bassett (Hayden Chase), Jodi Fung (Nurse), Braeden Marcott (Salesman), Jared Poe (Young Agent), Nick Jameson (Lazlo Drake), Sonia Braga (Elena Derevko), Isabella Rossellini (Katya Derevko), Andrew Divoff (Lucien Nisard), Jeremy Brandt (Lead CIA Agent)
Plot Outline:
After a tactical group infiltrates the DSR and steals Rambaldi artifacts, CIA director Hayden Chase discovers that the alarms at the DSR were disabled from Nadia's computer, allowing the raid to happen, and 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 Syd and Nadia, is Elena Derevko. They follow her trail to a dead Rambaldi follower, a stunning betrayal, and a presumed dead family member...
