Although the war against Valentine is over, Clary and her friends problems are not over yet. After Simon is approached by Camille, one of the oldest vampires in the world, Simon’s life changes for the worst. Shadowhunters are getting murdered all over New York, and strange men in grey tracksuits are following him round. What they don’t know is that Simon now has the mark of Cain, meaning that anyone who tries to harm him would have the damage come back at them seven-fold Simon, Clary, Jace and the Lightwoods must figure out who is killing the Shadowhunters and why Simon is receiving continuous threats to his life. But what they find out is not pleasant, and they must stop the person behind it before it is too late.
As the author originally intended to stop this series at book three, I was interested to find out what was going to happen next, as the previous story line had already been concluded, meaning that Clare needed to come up with a completely new problem for the characters to face. Although I loved this book, I felt as if the story line in the previous books was stronger. I also thought there should have been more issues needing to be resolved to go into the next book with, as at the end there is only one problem left. I also felt that some of the characters needed development. For example, near the start of the book, Camille is seen to be one of the most powerful and oldest Downworlders in existence, but as the novel progresses she seems to become weaker and less important. As there are only two bad characters who has survived at the end, I felt as if her character should have been developed further, as I am sure it will be continued into the next book.
Overall I enjoyed this book and will continue to read this series. I have enjoyed seeing how the characters have grown and changed through the course of the series, and how relationships have progressed. It is nice to see how there are both gay and straight relationships, as in the majority of novels, all the relationships are between a heterosexual couple, and gay relationships are seen in a negative light, whereas the relationship between Alec and Magnus is seen to be no different to the one between Jace and Clary. The book is continuously exciting with lots of action scenes, and there is never a dull moment, as even the slower parts are interesting, as you get to learn more about the characters and the plot. I am looking forward to reading the next book in this series.