City of Lost Souls is the fifth book in Cassandra Clare's The Mortal Instruments series.
We left off in book 4 with the demon Lilith being destroyed and Jace and Sebastion are now missing. When the Clave gives up the search for them, Clary and her friends band together to search themselves. When they finally find Jace he is "changed". Clary is ecstatic to know he's still alive but desperate to try to get "her" Jace back. One big problem... Jace and Sebastion's life forces are joined. This forces Clary to convince Sebastion that she has forgiven him in order to get close enough to find a way to seperate them. If the Clave finds out where Jace and Sebastion are they will kill either one at the first chance they get. Will Clary find away to save Jace before it's too late?
This book had a lot more romance and relationship building then the previous books. Not only do we have Jace and Clary's relationship, but Simon's and Alec's as well. We got a lot more of Magnus in this one - he cracks me up! Simon is proving that he's really not the monster that he thinks he is and he has been an amazing friend to Clary. I'm glad Clary is finally realizing this. The chemistry between Jace and Clary was touching as usual. Them kissing or even holding hands is as good as some of the sexier scenes in some other novels. I was glad Cassandra Clare didn't end it with a huge cliffhanger like the last book. I almost through the book across the room screaming "Noooo!" when I finished book 4. This book had a little different feel to it then the previous books since there was a little less action and more on the characters but I loved it. This is one of my favorite YA series and this book certainly didn't disappoint.