The Blue Castle is a novel by L.M. Montgomery that follows the story of Valancy Stirling, a 29-year-old woman living in early 20th-century Canada. Valancy is trapped in a dull and oppressive life, suffocated by her controlling family and societal expectations. She yearns for freedom and adventure, often dreaming of escaping her mundane reality. When she receives a shocking diagnosis, it prompts her to reevaluate her life and make bold choices that lead her on a transformative journey.