I was really apprehensive about this book. I'll be honest City of Fallen Angels did not impress me at all. It left me wondering about the characters that I actually liked from the first three books of the series and there was too much angst. I couldn't stand it. 
 So here is where I admit that City of Lost Souls brought back that feeling I had when reading the original trilogy. Yes, bad things happen to the characters we've grown to love, but it just didn't seem so angsty. Jace wasn't beating himself up every page because "he doesn't deserve the life he has or Clary". Honestly, it makes a difference without all the self-hatred. 
 At the end of City of Fallen Angels Jace is gone with Sebastian. We see in the last scene that Sebastian performed a ritual that seemed to link himself and Jace together and then they vanish. So after waiting for about a year to find out how the story plays out from there, we finally get our answers. Sebastian is alive of course, but what does he want with Jace, and why is Jace with him? These are questions our Shadowhunters need to find out before the Clave who, thinking Jace has switched sides, now wants to kill him. The friends split up in order to help find out how to save Jace before it's too late. 
 This book for me took the events of the previous book and made the characters really grow from that. Yes, Clary is still impulsive, but by the end she understands that sometimes you have to make the tough decisions. Jace too, who for most of the book is under Sebastian's thrall has moments of clarity where he understands the sacrifices that need to be made, and he also comes to realize that he deserves way more than he thought he has since the beginning of the series when he thought he was really Valentine's son. It makes both of them better and I hope it sets up the final book in a good way where they will continue to be strong. 
 I always thought that Clare did a good job with the more secondary characters and she still doesn't disappoint. Izzy, Alec, Simon all continue to grow and realize what they need and deserve out of life. Izzy realizes it's ok to rely on people. Alec, maybe a bit too late, realizes that you just have to live the present and not worry about the future. Hopefully, this will be something he fights for in the next book. And Simon realizes that even though he's a vampire he's not a monster and does deserve to be love and can love in return. 
 This book has renewed my faith in the series. I don't know if the last one was just a fluke or if Ms. Clare just really has a huge plan set out for this series. Either way, I'm glad I stuck with it and can't wait to see how it all ends. Until Then!