Nightwatching

How best to describe Nightwatching by Tracy Sierra? Psychological Thriller? Yes. Suspenseful? Yes. Claustrophobic? Yes. Creepy as hell? Definitely.
The tension mounts chapter by chapter, but midway Sierra moves the goalposts so that you are left thinking “hang on, what's going on here?” Then, as we reach the final third, it all starts to make sense again.
We learn some of the heroines background throughout the story. These tend to break the tension, and can be a little annoying when they crop up just as things are getting interesting.
Not one of the characters in this book has a name. This should have been irritating, but I became so invested in the story, I stopped noticing.
Many thanks to Netgalley, Viking Books and Penguin Random House for the eARC in exchange for this review.