In 1768, in the midst of a severe smallpox epidemic that killed every tenth inhabitant of the country, Empress Catherine II decided to set a personal example to her subjects: together with her heir, Tsarevich Pavel, she was the first to be vaccinated against the terrible disease and declared vaccination mandatory for everyone — despite court intrigues, peasant riots and the impending war with Turkey, This decree must be implemented at all costs, otherwise the deadly virus will claim even more lives.