Several people I know had raved about this book, so I was disappointed not to find it very satisfying. I thought it started well, with a tragicomic depiction of a woman whose life was a series of tragedies, many of them self-inflicted.
The main character is Nora Seed, a 35-year-old English woman. Unhappy with her life, she overdoses, and finds herself in the Midnight Library, which contains an infinite number of books, each of which corresponds to a potential life, depending on the choices she'd made. A librarian, in the form of one of her former teachers, explains the mechanism: choose a book, start reading it, and you find yourself in that world.
The librarian is a walking, talking fortune cookie. Her pseudo-profound announcements were a source of great irritation.
I won't explain the whole plot, but essentially Nora explores various lives, and finds none of them satisfactory. As the disappointment of each climaxes, she finds herself in the library once more. Finally — and I'm sure every single reader of the book must have seen this coming — she finds its her "root life" that's ideal. All she has to do is to change her attitude to it.
When Nora is in lives in alternate realities, she essentially hijacks the version of her who lives there. She has none of the hijacked version's memories, but is now in control of that person's life, making decisions for her. The "root" Nora then leaves, and the hijacked Nora has a hole in her memories.
This brings up an issue that the author either never thought about or chose to ignore: the book is all about the choices we make in life. But if your life is hijacked by an alternate you from a different dimension, you're left to live with the consequences of the actions the other you made. For example, Nora has sex with a complete stranger, who is also a traveler between dimensions, apparently with no thought about whether the person who's body she was hijacking would consent to having her body used in this way. Perhaps that Nora got pregnant from the encounter? Tough luck, that Nora!
Perhaps "root" Nora had been hijacked many times in her life? That would have been an interesting issue to explore. But the author doesn't go there.
For an exploration of alternate timelines, I'd recommend instead "Version Control" by Dexter Palmer, which I found far more satisfying.
