A woman with nine sons longs for a daughter, and when she finally gives birth to a girl named Kerttu, an evil creature named Suyettar tricks the boys into believing they have a new brother, causing them to leave home. The mother, heartbroken, eventually dies, leaving Kerttu determined to find her brothers. She embarks on a journey with her dog, Musti, and is soon joined by Suyettar, who pretends to befriend them. Suyettar attempts to lure Kerttu into dangerous situations, but Musti warns her each time. Eventually, Suyettar kills Musti, and without her companion's warnings, Kerttu is tricked into bathing with Suyettar, resulting in a magical transformation where Kerttu becomes an old hag and Suyettar takes her appearance. Suyettar deceives Kerttu's brothers into believing she is their sister, while Kerttu is forced to serve her. Kerttu, despite her disguise, sings a sorrowful song that eventually catches the attention of her brothers. They investigate and, upon learning the truth, devise a plan to rescue her. They trick Suyettar into bathing Kerttu's eyes, allowing her to regain her true form. The brothers then trap Suyettar in a sauna, where she is destroyed. Kerttu and her brothers return home to their mother, who is overjoyed to be reunited with her children. The story concludes with a sense of family restored and the triumph of good over evil.
By Parker Fillmore · First published 1939 · Genre: Fairy Tale, Fantasy, Adventure