Miri finally helps them banish the man who has been stealing their money. She meets the three royal cousins - Astrid, Felissa, and Susanna, nicknamed 'Sus.' The girls hunt and fish to survive their promised money from the king stopped coming when their mother died. The king agrees, and Miri travels to Lesser Alva, a swampy area of Danland. Despite the king's threats, Miri bargains that she will accept on the condition that she and the other graduates of Mount Eskel's Princess Academy become the owners of the land in their province. He asks Miri to travel to Lesser Alva, where three of his cousins live, to be their tutor and prepare them to come to Asland and meet the king. In order to secure a good relationship with Stora and avoid war, the king has decided to establish a princess academy and offer a bride to Stora's King Fader. Miri is about to leave Asland to return home to Mount Eskel when she is summoned by the king, who explains that the neighboring kingdom of Eris has been conquered by Stora. and could move forward with the storytelling' for Forgotten Sisters. Because Princess Academy won a Newbery Honor, Hale felt 'fear and pressure' in writing a worthy sequel however, after releasing Palace of Stone, she had 'dealt with fear. Hale wanted to explore that setting and the story of the three girls who are members of the royal family.

In an interview with Publishers Weekly, Hale commented that her idea for the plot of The Forgotten Sisters stemmed from a mention of a swamp region in the original Princess Academy novel. It follows the story of Miri Larendaughter, who becomes a tutor to three royal cousins in a new princess academy in the swampy land of Lesser Alva. It is the third and final installment of the Princess Academy series, preceded by Princess Academy: Palace of Stone. Princess Academy: The Forgotten Sisters is a fantasy novel written by Shannon Hale and published by Bloomsbury USA in 2015. Princess Academy: The Forgotten Sisters, Bloomsbury

Princess academy series in order