Yekaterina "Katya" Derevko, alias The Black Sparrow, was the second of the three Derevko sisters to be introduced. She was a Colonel with the SRV (Russian Intelligence) and later allied with the Covenant.
Katya was sent by Irina to help Jack rescue Sydney and Vaughn from a North Korean prison (3.12). She confirmed Sydney's survival, but offered to help with her extraction on the condition that Jack murder Arvin Sloane as a "preventative measure." He agreed and she took Jack to meet her contact, Mr. Cho, to collect on a debt he owed her. When he declined, she stabbed his hand and ordered him to call Mr. Kwan.
When Jack went to Sloane's office to assassinate him, Katya called him to inform him, he was never safe - not even from his friends - and to back off of Irina. She then called Jack to tell him the plan was off (he was just a pawn to threaten Sloane). Following the mission to rescue Sydney and Vaughn, Jack confronted her about Irina's intentions. She told him that it would one day be clear to him and then kissed him passionately on the mouth before she walked away.
Later, while Sydney and Vaughn were on a mission to an inactive Russian bunker (to track down Sloane), Katya turned on her fellow Russian guards to aid in their escape (3.21). She revealed to Sydney that she was her aunt. She also told her that Irina had given birth to her sister, Nadia, in a Russian prison after she left Jack. The baby was taken away from her when she was one day old and Katya has been helping Irina locate her ever since. She was deeply distraught to learn that Nadia was with her father, Arvin Sloane. She later flirted again with Jack, who rebuffed her advances.
When Vaughn kidnapped Lauren and was about to disfigure her, Katya stabbed Vaughn from behind (3.22). She set up a trap for Sydney in Palermo, but when she tried to shoot her, Sydney had already removed the clip from her gun. She was then shot by Sydney, who missed, allowing Lauren to escape in the process. Katya is arrested.
Nadia visited Katya in her federal prison cell (4.15). She fondly recalled her childhood with her sisters. Although she was desperate to see Sydney, Nadia refused to talk about her. After she confessed to Sydney that she had been visiting Katya to learn more about their mother, Sydney told her that Irina had hired an assassin to kill her. Sydney then visited to demand Katya leave Nadia alone - she swore neither she nor Irina would ever harm Sydney. She then gave her a lead which Sydney followed to find the real would-be assassin.
When they were trying to track down her sister, Elena, Jack came to her for information (4.20). She demanded a full pardon and immediate release in exchange. Jack swore to do everything in his power and Katya revealed that Elena had been acquiring Rimbaldi artifacts for years through her front - The Covenant. She said that she could help find her, but only Irina could have stop her (Jack supposedly killed Irina). It is left unanswered whether Jack ever helped aid in her release.
Parents: Mother (name unknown, deceased), Father (name & status unknown)
Brother-in-Law: Jack Bristow (deceased)