I loved this entire series and I was pretty excited to see how everything would end in this book, I was very happy with the end to this series.
Everyone knew this book would end with Jace and Clary together and with everyone happy in some way or another and despite the fact that I knew it was all going to be okay, I loved this book. It didn't beat City of Glass, which was the original final book and my favourite book in the series, but it did a good job of surprising me while wrapping up everyone's stories.The thing that annoyed me most about this book was how much it discussed the prequels, The Infernal Devices, although I haven't read them, I have wanted to and now I kind of know how they're going to end. I know it was probably really cool for people who had read the prequels to see how the characters ended up and how everything tied together, but it just annoyed me that now if I read them I won't really be surprised by anything that happens, and I think there could've been a way for her to do that without giving as much away as she did. I was really sad when I finished this book and for a while I couldn't work out why, because although it did make me cry near the end, the epilogue gave it a happy ending, but then I realized that I just really loved this series and it's characters that always had me laughing (I mean "salt my game and I'll stake you"? Iconic.) and I was just sad to know they wouldn't have any more stories. My favourite character in this book was Simon, I love every character, which can be seen in all my previous reviews of the other books, but I feel Simon really goes under everyone's radar and Cassandra Clare brought that to my attention loud and clear with this book. His love and compassion for everyone, his scene in the cave with Alec, his hilarious banter with Jace and his sacrifice in the end just showed how well rounded a person he is and made me realize how much I enjoyed his character's constant presence. I also really liked Emma and I'm going to read the Dark Artifices just to see what happens to her. I would recommend this series to anyone who likes young adult paranormal fiction.
Also if you live in Australia (or I hear also UK) you get a comic strip from the prequels and a cool poster included at the end of the book.
The book starts with Sebastian's attack on the Los Angeles Institute where Emma Carstairs, her best friend Julian and his younger siblings escape to Alicante from, but not before Sebastian turns all the others in the institute into endarkened ones. All the shadowhunters must then travel to Alicante so they can decide on what they are going to do against Sebastian and his growing army. Before all the Shadowhunters evacuate Sebastian tries to attack the London institute but is stopped by a force that many people didn't know about (and I assume it's a ghost or something from the prequels) and don't quite understand, so wanting to win a battle he burns down the Praetor Lupus headquarters and kills all the wolves in it. He then stabs Jordan in front of Maia and tells her to deliver his message of join with him or die to all the other downworlders and just before leaving says to her "your boyfriend's dead, by the way" and she's left clutching Jordan's dead body. Sebastian launches an attack at the Adamant Citadel and the Clave fall into his tricks despite Jace and Clary's warning that he no doubt has more soldiers than what they can see laying in wait so they run through the portal before the Clave can stop them and when Sebastian stabs Jace, the heavenly fire in him injures Sebastian and he and his army retreat. Brother Zachariah then tries to help heal Jace but the heavenly fire that is out of control in him latches onto Brother Zachariah and turns him back to his original shadowhunter state (another character from the prequels). The next night the downworlder representatives and Jocelyn are invitied to a dinner in the faerie court, but they are taken hostage because the faeries have allied with Sebastian. That night Sebastian comes to Clary's room as he knows she'll be alone and holds her in place with a spell while he tries to convince her to come rule with him, after she refuses he tries to force himself upon her similar to the last book but then Jace comes in and stops him. The next day, with the help of Emma, they realize that the reason no one can find Sebastian or his prisoners is that they're in Edom, the demon realm of hell, which can only be accessed through faerie court so Jace, Clary, Alec, Isabelle and Simon portal there together. They quickly realize that the faeries have betrayed them and Alec, mad that they've taken Magnus, shoots Meliorn in the heart before they get the Queen to show them the way to Edom. Once there they quickly take refuge in a cave for the night and realize that this world is a mirror to theirs except in this world the shadowhunters were defeated and demons scorched the earth. The next day Jace ventures out and encounters the ghost of the Iron Sister he killed when Sebastian was controlling him and she goads him to lose control of the heavenly fire and he blazes up the entire desert. Clary uses a fireproof rune to approach him and they control the fire in a way they won't tell the others. That night with the heveanly fire under control Jace and Clary sneak away from the others and (finally) have sex, which really prompts me to ask, why when they were going on a mission to kill Sebastian did Jace think to pack condoms? The next day when they reach Sebastian's headquarters, they split up and while Izzy, Alec and Simon find the prisoners Clary agrees to be Sebastian's queen if he seals off this world from theirs, saving everyone in it. He starts the process and it forces everyone into the room they are in and they see Clary on the throne and think she's betrayed them, until he asks her to kiss him to show that she's loyal and she stabs him with her blade that she had used the first rune she ever envisioned to trap the heavenly fire inside. While dying, the evil is removed from Sebastian and Jonathon tells them he was sorry and to throw the infernal cup in his runes to destroy the endarkened ones, which they do. They then must call upon Magnus' father Asmodeus to send them back to their world, but as he as a demon he won't do it for free and requests Magnus' immortality, which will kill him because his age will catch up with him. As Magnus is trying to convince them it's the only way, Simon offers himself up and Asmodeus takes him, but also takes all his memories of the Shadow world so he won't remember any of them. The epilogue is set six months later at Jocelyn and Luke's wedding where Alec's father finally tells him he is a good man and he and Magnus decide to stay together no matter what, Clary and Jace discuss their future wedding, Maia and Bat rekindle their old flame and Magnus manages to restore some of Simon's memories and he and Isabelle discuss him becoming a Shadowhunter.