To save her mother's life, Clary must travel to the City of Glass, the ancestral home of the Shadowhunters -- never mind that entering the city without permission is against the Law, and breaking the Law could mean death. To make things worse, she learns that Jace does not want her there, and Simon has been thrown in prison by the Shadowhunters, who are deeply suspicious of a vampire who can withstand sunlight. As Clary uncovers more about her family's past, she finds an ally in mysterious Shadow-hunter Sebastian. With Valentine mustering the full force of his power to destroy all Shadow-hunters forever, their only chance to defeat him is to fight alongside their eternal enemies. But can Downworlders and Shadowhunters put aside their hatred to work together? While Jace realizes exactly how much he's willing to risk for Clary, can she harness her new found powers to help save the Glass City -- whatever the cost? Love is a mortal sin and the secrets of the past prove deadly as Clary and Jace face down Valentine in the final installment of the New York Times bestselling trilogy The Mortal Instruments.
This book is definitely my favourite of the series so far. It follows Clary as she travels to idris in search of an antidote for her mother, however while there she meets Sebastian, unaware that he is a spy for Valentine. As Clary goes on her mission, with the help of Magnus and Jace she discovers more secrets from her past that cause a trail of actions that can change the Shadowhunter world forever. I loved this book, it was absolutely incredible. I found myself so over-excited when i became close to the end as you find out the secrets from Clary's past and all the truth comes to light after Valentine's lies. I found myself in tears at multiple points throughout this book and the ending was just incredible. I'm a big sucker for hapy endings and i am so glad that this is what i got. I can't wait to read the next book and find out what is going to happen next.