"The Blue Castle" is a novel written by Canadian author L.M. Montgomery, published in 1926. The story follows Valancy Stirling, a 29-year-old woman who feels trapped by her overbearing family and societal expectations. After receiving a life-changing diagnosis, she decides to embrace her desires and seek happiness. Valancy's journey leads her to the Blue Castle, a place of freedom and self-discovery. There, she meets Glen St. John, a man who challenges her views on life and love. The novel explores themes of individuality, love, and the pursuit of personal happiness against societal norms.