The film is based on a true dramatic story of the fate of a wonderful Russian woman - Countess Yulia Petrovna Vrevskaya, one of the first Petersburg beauties. The events of the movie take place during the Russian-Turkish war for the liberation of the Bulgarian people from the Turkish yoke. An early widowed baroness, having left Petersburg, and having invested all her money in organizing a volunteer sanitary detachment, she becomes a sister of mercy on the front of the Bulgarian war with the Ottoman Empire of 1878.