A pupil of a Carmelite monastery, a young Frenchwoman, Marie-Claire, comes to Russia, where the Russian Countess Orlova is in charge of organizing her fate. The Countess, a friend of Marie's late mother, hopes to successfully marry the girl off. But love breaks all plans. The dowry's chosen one, the brilliant officer Prince Alexander Potemkin, pays absolutely no attention to her. In desperation, Marie commits a rash act - all of St. Petersburg learns about her dishonor, and now she has two options: return to the monastery or marry a rich old man. But an unexpected turn of fate brings Marie-Claire to the Caucasus in the midst of war, where she is entrusted with a secret mission. Here she meets Prince Potemkin again - now the salvation of her lover and the lives of hundreds of Russian soldiers depend on her...