First thing first: I don't like story about serial killer and I avoid reading story where children are killed.
That said I read this book in two sitting because I couldn't put it down.
Holly is a great characters. she's damaged but she's also able to feel empathy and to get into the mind of the killer. A brave, kickass heroine who's able to be tender with her brother.
The plot is gripping, it builds the suspense slowly but once you're hooked you have to read as fast as you can and I nearly stopped breathing (metaphorically) during the last chapters.
It was one of the best thriller I read in quite a long time: gritty, enthralling, never over-violent.
An excellent read, I strongly recommend it.
Many thanks to the publisher and Netgalley for this ARC, all opinions are mine.