Nora Seed is the main character in the novel "The Midnight Library" by Matt Haig. She is a thirty-something woman who struggles with feelings of regret and dissatisfaction in her life. After a series of unfortunate events, Nora finds herself in a magical library that allows her to explore different versions of her life based on the choices she could have made. In the library, each book represents a different life path, giving Nora the opportunity to experience alternate realities. This journey helps her reflect on her past decisions and ultimately leads her to discover what truly matters to her.