SPOILERS
The following summary covers all seasons and episodes of the show, so don't read if you haven't seen them all!
This is the fanlisting for the relationship between Irina Derevko and Sydney Bristow on tv show Alias. Sydney grew up believing that her mother, Laura was a loving teacher that died when she was a child. Now an adult, and working undercover for the CIA, she finds out that her mother is in fact a former KGB agent, sent to seduce a senoir CIA officer, her father Jack, and retreive classified intel. Once her cover was blown, she faked her own death and escaped the United States. Jack raised Sydney in the lie that her mother was dead.
Upon finding out the truth, Sydney tries to find her mother and reaslises she is one of the enemies she is fighting agaisnt. They come face to face in Taipei and Irina shoots her daughter in the shoulder - she clater explains that it was to prove her loyalty to her aassociates and allow Syd to get away.
Days later, Irina turns herself into the CIA, demanding to talk only to Sydney. At first, she refuses, truly hating her mother, but soon finds herself with no other choice but face her mother again. Irina proves herself by giving a lot of intel and Sydney starts to trust her mother and they actually start to get close, until Irina stages her own getaway and starts working with Sloane to fulfil Rambaldi's endgame.
Betrayed, Sydney still has cofused feelings about her mother. When she is thought dead, Irina helps Jack try to find out what happened to her and later helps her out of trouble - although undirectly. Yet, Sydney finds out her mother is dead, killed by Jack. He explains that Irina was trying to get her own daughter killed and Jack murdered her to protect Sydney.
Sydney and Jack later find out that Irina is actually still alive, and the woman he killed was a double. Irina never wanted to have Sydney killed and it was a set-up orchestrated by Elena Derevko, who also had Irina kidnapped. Jack, Sydney and Irina go to her rescue and enlist her help to foil Elena's plans. With Elena taken down, Jack lets Irina escape.
Irina later reappers and helps Sydney give birth to her child before disappearing again. She makes her ultimate appearance in the series final and reveals herself as the 'Big Bad' She has been manipulating them all in order to fulfil Rambaldi's prophecies