"By Pen and Sword" is a historical series based on Valentin Pikul's novel of the same name, set during the realities of the Seven Years' War. The events take place at the Russian court in the mid-eighteenth century. A French ambassador and secret spy from Versailles, Chevalier Charles d'Eon, arrives. Few suspect that he will soon become one of the main figures in military reports and the most wanted person in Europe. After living 48 years in a soldier's uniform, he unexpectedly has to change into a dress and trade his sword for a pen.