Played by Rebecca Ferguson
(played by Rebecca Ferguson)
In 1950s Soviet Moscow, Katya is beautiful and enigmatic. The daughter of two anti-Stalinists who were brutally taken from her when she was a child, Katya is now an apparently loyal member of the Communist Party, employed as a school secretary. However, Katya is deeply driven by the loss of her parents and secretly works as a spy, under the leadership of her cell leader, Misha. When Misha pushes her to start a relationship with Kremlin star Alexander, Katya’s undercover work starts to unravel and she commits one final betrayal to save Alexander.