The Kingdom of Back follows Nannerl Mozart, the older sister of Wolfgang Amadeus Mozart, who is a gifted musician struggling against the gender constraints of the 18th century. Desperate to be remembered for her own talent, she makes a dangerous pact with a mysterious stranger from a magical realm known as the Kingdom of Back. As her brother’s fame grows, Nannerl must navigate the consequences of her deal and the blurring lines between her reality and the enchanted world.