What a very odd book
The plot: Something is driving people mad when they see it - and is book is about the struggles of people to survive, and in particular one mother and 2 kids.
Nothing is ever explained about why people are going mad, it is just known that if you see this mythical something then you will go mad. Think of it like the Happening (M Night Shymalan film where plants did a similar thing) but nothing is ever really found out why.
So what we end up with is a great idea, but something that is very difficult to put to page. Some of the book works really well, building up a sense of unease and suspense in the reader - but some didn't work as well for me (the jumping between 2 times and the internal monologue). This is not to say it isn't well written, it is, but it didn't push my buttons at certain points.
Well worth a read