Decent enough read that I could recommend it, but nothing I would be actively following waiting for a second book.
I loved the POV that we had in the book. I liked the single consciousness feel, pretty much putting you in Ella's mindset and keeping you there. It does get a bit repetitive though, as other reviews have said, she is sick through out the entire book and the push and pull off getting her to do anything kind of grates the nerves. Specially with how the book ends.
Personally I'm not a fan of the "and everything was vaguely sorted" endings. It all seemed very textbook and rushed, something that didn't really leave me wanting more. When Ella calls up her professor to say she's dropping, I don't really know where the author was going with that. Her entire struggle through college, life and through this trip was everything she was/is. You don't feel any personal growth for her choosing to be in contact with friends again by giving up everything, but more that she is throwing everything away so she doesn't have to confront her past.
The 'haunting' part of the story was more build up, then actually putting the pieces together. You were only given "I know how to do this" without the character ever going through with it, which was frustrating obviously but gave the story good enough pacing. Again as other readers have pointed out you don't really know if things are actually happening because Ella is sick throughout their stay but it's not enough for her to actually seek out medicine or rest so you don't feel sorry for her as she gets worse.
So, perfect quick no-feelings-attached kind of reading.