- Siblings: Irina Derevko (deceased), Katya Derevko
- Nieces: Sydney Bristow, Nadia Santos (deceased)
- Grandnieces & nephews: Isabelle Vaughn, Jack Vaughn
Before Season 4
Elena was one of the KGB's foremost assassins, responsible for the murder of countless diplomats and politicians throughout Eastern Europe. Thirty years before Season 4, Elena disappeared and could not be found even by her sister Irina. Little did they realise that Elena had posed as "Sophia Vargas", the head of the orphanage Nadia Santos, her niece, was at (A Clean Conscience).
A hit was ordered on Sydney Bristow's life and Jack Bristow believed it was ordered by Irina (Resurrection). In retaliation, Jack found Irina and shot her (Another Mister Sloane). He did not realise that firstly it had been Elena who had ordered the hit under the guise of Irina, and secondly that he had in fact shot a doppelgänger of Irina's (Search And Rescue).
Around a year before Season 4, Arvin Sloane and Jack Bristow had been investigating the whereabouts of Elena. Jack received a message from an old associate that led him to one of Elena's safehouses in Warsaw. Inside was detailed information on the lives of Sydney Bristow and Nadia Santos, her nieces, with evidence suggesting she had them under surveillance for at least a decade. They assumed she was responsible for the attack on "Sophia", not realising that she in fact was Sophia (A Clean Conscience).
Elena arrived in Los Angeles, disguised as "Sophie Vargas". She used her former connection to Nadia to stay with her and Sydney so as to monitor their work for the CIA. She claimed to have been attacked in her home in Lisbon, Portugal, the reason for her coming to the United States. She gave Nadia a necklace with St. Marcos on it, who Nadia's orphanage was named after. Nadia took it, but did not know that Elena had implanted a microphone into the necklace so she could monitor Nadia's conversations and CIA work (A Clean Conscience).
She later offered to cook dinner for Sydney, Vaughn, Nadia and Weiss. Sydney and Vaughn were unable to make it because of Jack's illness, so only Nadia and Weiss attended. Elena took the opportunity to have her associate, Avian, hack into Nadia's laptop and request to move the Hydrosek, a deadly weapon, to an unsecured location away from APO. Elena and Avian then went to the site and stole the weapon before Nadia and Weiss could arrive to stop them - albeit not realising who it was that stole it (Mirage).
Elena sent a team into the Department of Special Research to steal all the Rambaldi artefacts necessary to complete "Rambaldi's endgame". On the same night, she left Sydney and Nadia's house, saying that she had been informed by the Lisbon police that it was safe for her to return. Hours later, Hayden Chase entered the house and accused Nadia of working against the government and allowing the team to break into the DSR. It was at this point that Jack and Sloane began to realise that Sophia was Elena, which was backed by the microphone found in the necklace given to Nadia by Sophia (The Descent).
Sloane deduced that Elena would go to Lazlo Drake with the Rambaldi artefacts. Sydney and Sloane went to meet him, but he was already dead. Sydney found a hidden camera and rewound the feed to see Elena talking with Drake. Before she can see where they planned to take the Rambaldi artefacts, Sloane tranquillized her and left. He met up with Elena in her office in Prague and offered his services to help complete what she was doing. Dixon, Nadia and Sydney were sent on a mission to try to stop them. Dixon found Elena and Sloane, but Elena shot him before he could react. When in the hospital, Dixon told Sydney that he saw Irina Derevko before being shot by Elena, who had Sydney's mother in captivity (The Descent).
Elena and Sloane constructed a massive Mueller device over the Russian city of Sovogda which, in conjunction with the tainted water supply from The Orchid, led the people of Sovogda with a severe infection that made them violent (Search And Rescue). When Sloane learnt that APO had sent a team into the city to try to stop them, he offered to head out with the team himself. While he was doing this, Elena began to transmit a subaudible frequency via the Russian mil-sat network to spread the infection world-wide. The second that the bombers were scheduled to destroy Sovogda, the frequency would be broadcast causing the effects of Sovogda to occur worldwide (Before The Flood).
One of Elena's men found Nadia walking around the streets. He brought her to Elena, who told Nadia that she never wanted to hurt her. She said that she always thought of Nadia as her daughter, then offered her a place alongside her. She showed Nadia a map of the world with pinpoints all over it, saying "the blood has begun, just a few will survive." Nadia refused to join her, saying that she would never kill Sydney as Rambaldi's prophecy had stated. Elena then infected Nadia with the infection with the aim of forcing her to kill Sydney (Before The Flood).
Elena noticed Sloane arrive back on the monitor. He was carrying a supposedly unconscious Vaughn, but as soon as they arrived in the base they began to shoot Elena's men. They were joined by Jack and Irina. They got to Elena and Irina knocked her to the floor with her gun. Sloane put Elena in a chair and Jack and Vaughn went to the computers to stop the mil-sat network from uploading the frequency. However, they could not retract the transmission. Elena told them that she had planned the attack for five years; it would not be that simple to stop her. Sydney managed to get into the main circuit board, but found a blue and a white wire. Irina did not know which to cut, and she asked Elena. When she refused to answer, she told Jack to start torturing her. Before he could do so, Elena told him to stop, and said to cut the white wire. Irina immediately shot Elena, and told Sydney to cut the blue, other wire (Before The Flood).
- Elena Derevko: The blood has begun, just a few will survive. (Turning to Nadia) There she is, I see her now. Your mother. She used to get me with those eyes. Its time that you accept the life you have ahead of you. I know its not easy. Greatness never is.
- Nadia Santos: You're right. I see my future. Two minutes from now I see myself killing you. The only reason you want me on your side is because you believe I am the one who is to stop Sydney Bristow. But she's my sister. You're nothing to me.
- Elena Derevko: I'm sorry you feel that way. (Before The Flood).