The action of the Russian-Turkish series "Kalbimin Sultani" takes place in the 19th century in the capital of Turkey. Anna, the daughter of one of the employees of the Russian Empire embassy in Istanbul, accidentally meets Sultan Mahmud II. The Sultan is immediately attracted to the beautiful and educated girl. He wants her to live in the harem and educate the heirs to the throne. However, for the Russian intelligence services, Anna becomes a potential agent to monitor what is happening in the corridors of power in the Ottoman Empire palace.