In the heart of London, Anna Khitrova, a midwife at a local hospital, delivers a baby girl from a teenage Russian girl who dies in childbirth. The only clue to the dead girl's identity is a diary written in Russian. Determined to protect the baby and uncover the mystery of the mother's death, Anna delves into the diary's contents, leading her into the dangerous world of the Russian Mafia in London. Her path crosses with Semyon, the charming but ruthless owner of the Trans-Siberian restaurant, who expresses interest in translating the diary for her unaware of his hidden agenda.

Complicating matters further, Anna encounters Nikolai, Semyon's enigmatic driver and the family's 'cleaner,' who is entwined in the criminal dealings of Semyon's son, Kirill. Nikolai's true intentions and loyalties are murky as he becomes a pivotal figure in the unfolding drama. As Anna unravels the grim secrets of the diary, she unwittingly triggers a chain of events that pulls her deeper into the violent and treacherous underworld of sex trafficking, betrayal, and vengeance. Her determination to protect the innocent child aligns her fate with Nikolai's, leading them both down a dangerous path from which there may be no return.