The vampires are really fallen angels, but they are divided amongst themselves. Some continue to side with Lucifer, but others need to stop the Dark Prince from waging war on heaven itself. In Melissa de la Cruz's final Blue Bloods novel, Gates of Paradise, the final battle is primed, but the risks are bigger than anyone imagined. 
 Schuyler has sacrificed everything to continue the work of her mother, the great angel Gabrielle, but nothing seems to have worked. Lucifer is still gaining power and the Silver Bloods have scared all the vampires into hiding. Schuyler and her best friend Oliver know they must protect the Gates of Paradise from the Dark Prince and his plans, but she doesn't even know how to find it. Mimi, on the other hand, has gotten over wanting to kill her heavenly twin for leaving her for Schuyler, but Mimi and Jack were called back to service by Lucifer. While they don't actually want to help the Dark Prince, they must convince him they are in his service in order to protect the ones they love; the problem is Lucifer is much smarter than even they, his trusted two, give him credit for. 
 Bliss is no longer a vampire, but she has folded into the Wolf Pack. With Fenrir and the other wolves at her side, she thinks they can give Lucifer a good fight to stop his corruption of heaven. The problem is she no longer has the powers as a new Red Blood that she once had as a Blue Blood. Just investigating the destruction of the Repository becomes dangerous, since she can't protect herself. But the true story lies with Michael and Gabrielle generations upon generations ago. How did they stray apart? What came between them? And what, ultimately, allowed Lucifer to get to this point? 
 My relationship with this series went up and down at times, but I actually really liked this conclusion. At a couple points in the novel, I was confused as to how everything was going to play out, but I was happy everything all eventually worked out in the end the way I wanted it to. Again, I liked the multiple stories carrying on simultaneously; it built the suspense and kept me going to find out what was going to happen next. Sometimes it got a little confusing, but I still liked the rotating perspective. 
 As for the series as a whole, I think this is a good series for middle readers who are just starting to branch out into YA books. It is a little juvenile at times, but the story matures with each installment. It always joke that it is "Twilight meets Gossip Girl", but it is certainly more than that. There is much more the the story behind the vampires, and the whole fallen angel angle makes this a unique story. I can't say I am totally sad to see this series end, because I was ready for it to conclude, but I did certainly enjoy it while it was going.