She was assigned to infiltrate the United States, and to gain the trust of Jack Bristow, then a CIA agent, in order to steal classified information regarding Project Christmas.

At the end of the first season, Sydney discovered that her mother was alive and also the mysterious criminal overlord known up to that point only as "The Man".

Later, during a mission in Panama, Irina did betray the CIA and joined forces with Arvin Sloane and Sark.

Her subsequent whereabouts were unknown throughout season three, although she continued to be in occasional contact with Jack via Internet Relay Chat.

Jack Bristow received permission from his superiors to execute Irina, and in "Another Mr. Sloane" he states that he carried out the act himself.

The fourth season finale revealed that a genetic modification procedure known as Project Helix was used to create a double of Irina, and it is this woman whom Jack shot dead.

The attempt on Sydney's life was placed by Irina's other sister, Elena Derevko, to mislead Jack into thinking he had killed his wife.

The woman who underwent the genetic therapy was an agent of The Covenant, Elena's own criminal organization, who had volunteered to take Irina's place and be assassinated.

It is revealed she had Kelly Peyton kidnap Sydney to recover information about the Horizon, a Rambaldi artifact that would grant its wielder immortality.

In the episode "Maternal Instinct" she reunites briefly with Sydney and Jack, during which they discover her affiliation with Prophet Five and Irina also indicates that she gave the order to kill Michael Vaughn.

Jack assumed that Sloane wanted to use the missiles not to simply destroy areas with high population densities, but to profit from the reconstruction.

She is a pivotal part of the fourth season, with her actions significantly affecting the lives of her nieces Sydney and Nadia.