Oh, folks. I don't think I've read a book quite like this one. This is a book about ghosts that also very much not about ghosts but about the interaction between people. While it contains some scenes that might be startling for some people, this book is absolutely worth picking up and sharing with friends. Cas is not your average ghost hunter, and Anna is nowhere near your average ghost. The rule of thumb goes that two not-average things must collide and you're left with a story full of surprises and moments that you might not expect.I thought it was a stand-alone, and I'm very much pleased that it is not.