More than half of the book simply bored me to death. The rest, that is the ending, I loved it, it was the perfect and most reasonable ending. So why didn't I like the first three quarters? Because of Cas... It annoyed me, I didn't connect with him, I didn't care for him. I wanted Anna, but Anna was in Hell... literally, so there was nothing in the book to alleviate the annoyance and boredom Cas, Thomas, Carmel and especially Jestine caused me. Even if I couldn't see an alternative to their story development. 
 If the reader can't stand the characters, little is left to mend the problem :( 
 Summarizing... If you liked Anna #1 because of Cas, you most probably will enjoy this second book. In other case, you risk to end up like me :( 
 --> things I learnt with Anna: terror and creepy things in English affect me very little... Ergo... I should try with Stephen King in English xP