I'm giving this book 2.5 stars, because while it was all over the place and I skimmed some parts of it, the last maybe 30% were really good, I think. The author makes some really tough choices and while the ending will not be to everyone's liking, I thought it was a brave move. I'm also guessing there will be a second book? It sort of sets the sequel.In reality, this is a good book, and I really liked the story, but it's the writing that's all over the place, and that kind of ruined it for me. The pace was way too fast, but slow at the same time. It's like, when I really needed things to happen fast, they dragged on and on. And in the beginning, everything happens so fast, I needed that to happen slower, all of it. At times I felt like I was missing some scenes, when in reality they haven't even been written. I didn't get to know the characters much, other than what the author basically tells you. There are four POVs that just randomly shift and it could get confusing at times, especially the timeline, I had no idea if the scene I just read happened before, after, or during the one I'm reading atm.Here's what I thought - if this story was focused on Colin and Cameron, held captive down there, if the author worked on this connection the two of them develop, this very subtle romance between them (without the weird silent talking)... it would have been an awesome book. If I'm being honest, I only really cared what was going on with them - being in Sam's head was really exhausting (he wasn't creepy, he was just an angry man with mommy issues), plus it takes away that mystery of what he's up to, because he practically tells you everything. Being in Amy's head just made me hate her. Being in John's head, I was so bored, and he came off as a psychic rather than an FBI agent with good intuition.What I did like about it was that Cameron's POV was first person, while all the others were third person. It really worked well with the story.In the end, the whole doubles thing was completely unnecessary - this is essentially Cameron's story, not Amy's.No graphic sex scenes of any kind, and even the violence was... mildly graphic. I wish the author took a chance on this - it would have made this story a million times more horrific and creepier. Don't think you'll be reading something similar to Kitty Thomas, because it's nothing like it. It's, what I would call, a clean read. Everything is sort of implied, but you don't see any of it.I got this for free and I didn't expect much though the blurb promised something a bit different than what I read. It's a good premise, but ultimately, it didn't deliver. I got close to DNFing a couple of times but I persevered and I'm happy I did. I say give this a try if you're not into dark erotica, but want something similar (minus the graphic sex and torture scenes.) It definitely is a bit of a darker read.