“Freely we serve
Because we freely love, as in our will To love or not;
In this we stand or fall.” –Cassandra Clare, City Of Heavenly Fire
In this dazzling and long-awaited conclusion to the acclaimed Mortal Instruments series, shadowhunters from all around the world are being taken away from their homes to the shadowhunter capital of Idris.  They are facing the greatest
danger they have ever known: Clary Fray’s brother, Sebastian, or more commonly known as Jonathan Morgenstern.  Shadowhunters are being captured and turned into an Endarkened with the Infernal Cup.  As far as anyone can tell there is no cure after you have been turned. 
The Endarkened resemble those of loved ones, which makes them even harder to destroy.  With all of the shadowhunters gathered in one place, it made them easier to capture.  Clary Fray, Jace Herondale, Alec Lightwood, Isabelle Lightwood, and Simon Lewis all fight to save their world, as well as the mortal world.  They’ve seen a world with no shadowhunters.  Ash and dust traveled with the wind while demons were seen everywhere and there was no evidence of there ever being human life.
Cassandra Clare captures the attention of many young teen readers in this award-winning series.  She describes everything in precise detail.  I would recommend this book to teenagers who like the supernatural or paranormal.  Readers who like mystery, suspense, and action would also like this series. This book will get readers hooked and kept up at night reading.  This is one the best series I have ever read. 
There are six books in the series: City of Bones, City of Ashes, City of Glass, City of Fallen Angels, City of Lost Souls, and the conclusion, City of Fallen Angels.  Cassandra Clare wrote a prequel series called “The Infernal Devices” which consists of three books: Clockwork Angel, Clockwork Prince, and Clockwork Princess.