Nora is planning to kill herself but while she is considering suicide she is taken to a new plain where there is a library with an infinite number of bookshelves filled with an infinite number of green books and the prospect of living an infinite number of lives. Then she sees a woman at a desk, her elementary school librarian Mrs. Elm. Mrs. Elm explains that Nora is neither alive nor dead. She is inbetween, perhaps in a coma. Nora is told that each book is a life that she can have. All she has to do is pick a book and she will begin living the story in the book. If Nora has doubts about the life, she will automatically return to the library and can select another book. The library gives Nora the opportunity to work out her regrets in her life. However, there is a catch. These opportunities will stop at some point. Neither Mrs. Elm nor Nora won't know when that time frame is up. It is possible that Nora will lose the opportunity to be in the library and subsequently die if she does not choose a life to live before that time comes to an end. It's a risk Nora must take.
The Midnight Library shows that a stagnant life is no life. Nora had many options to choose for herself. She could have been a glaciologist, Olympic swimmer, rock star, pub owner, wife and mother, or a philosopher. Nora was indecisive and couldn't pick which goal to pursue. So, she did nothing. As one character told Nora, she has life fright. It is worth considering what makes your life worth living and which life dreams are what you really want.