1745. The reigning Empress Elizabeth Petrovna is infertile. The only heir is her feeble-minded nephew Peter III. Elizabeth cannot allow Peter to ascend to the throne, so she decides to marry the tsarevich, wait for the birth of her son, and then take the boy and raise him as a real Russian emperor herself. Brides are coming to St. Petersburg. Among them is the lovely Fike - the young Princess Sofia Frederica from the impoverished branch of the Prussian kings.