This book is a diary written by the last person on earth. It’s not initially clear what happened to everyone else, but we find out that she has been alone for some years, travelling around in abandoned cars and living in various interesting abandoned buildings (such as museums). It becomes clear that she is becoming a bit unhinged; understandable in her circumstances. To me this book reads like a study in memory, regret and self-deception, though that makes it sound a bit grim; there is a fair bit of humour in this book. The overall tone is reminiscent of Markson’s This is Not a Novel. Wittgenstein’s Mistress is more conventional, but that wouldn’t be hard: it’s still a strange, amusing and unsettling read.
If you don’t already know a lot about the history of philosophy, you will by the time you’ve finished this book. If you do, then you’ll recognise a lot of it. Like Goldstein’s more recent 
Demian is very mysterious and alluring. This book is about him and his influence on the narrator — they first meet when they are both schoolboys. Demian then turns up repeatedly as the years go by, gradually taking the narrator into a circle of freethinking misfits. It’s less fanciful than the other Hesse novels I have read, but still packs a bit of a punch.