I'd do nothing but reading if I could (ok, maybe eat some great food, buy some fancy shoes between two books...oh, and spend some quality time with the gorgeous guy I married while I am on reading-break anyway...)
The heroine behaves immature and stupid most of the time.
Relationships between her and the other characters change constantly. Nik, the master vampire, whom she saved in the last book, is suddenly not an ally, but a captor whom she tried to flee from multiple times. Derrick, with whom she had such a deep connection in the first part, now is just a nuisance - she has to save him from basically suicide with a five-minute-talk. (including ogling him - totally inappropriate and cringe-worthy). Emily is only there to show what a great person Melena is, because she's taken in a lonely teenager and cares for her.
Oh, and all guys want her and pester her with sexual innuendo constantly (Derrick, the werewolf, Nik, the vampire, and Lucas, the allmighty Nephilim). Bad Anita-Black-Moment.
Melena is unfortunately so stupid and caught up in herself, that the demon infestation in a neighbor town doesn't interest her much, although she as a sensor is one of the few people who could save the humans. She refuses to help more than once. Still Lucas comments as to how she always wants to help humans. Not that I can see, but that is just one instance where the showing is against the telling.
Also she has some brilliant moments of genius when she threw temper tantrums, e.g. when Lucas who has experience with demon possession asks her to only observe the interrogation of the first demon possessed she ever saw. She wass mad at him and wanted to blow the whole "I save innocent humans" action. Very mature and selfless...
Then they had to infiltrate a supranatural night club, where humans were only allowed as arm candy basically. As she was very, very secretive about her secret sensor abilities (unless it was one of those instances where she shows it to everyone around), she is to play the human arm candy. Her inner musings when asked to leave her purse at home:
"A moment of indecision overtook me. Could I do this? The independent woman inside railed against the idea, but it was the only way into the club if we wanted to keep a low profile."
Wow, just wow.
There are more of those scenes when her stupidity and self-absorption are nearly over-whelming.
This is one of those books, I just can't bear to finish, for stupidity alone.
(PS: I am not even starting on the drooling that she does over every man that crosses her path - vice versa of course, but nothing coming out of it)
(PPS: Also hate-worthy is the bad Mary-Sue-Moment when one vampire guard hurts her and all three males - Derrick, Nik and Lucas - get crazy mad and protective. The guy gets killed for it, so chill down. She got a scratch that was healed instantly. Also inconsistent, if Nik is really the big bad ass master vampire. A small time guard like that going against a direct order? Not looking too good.)