I keep on picking up this series out of mere habit rather than any real desire to read it. 
 I've said it before: This should have ended at book three. This story was done at book three. 
 All right, I had high hopes for the conclusion here: What's going on is pretty cool. After my love/hate relationship with the previous book, and Sebastian's dimension-hopping, I had to know how this finished. And here we're entering another alternate dimension, one that Sebastian more or less rules, which happens to be a demon realm. 
 Which was really cool, and I would have actually liked to see more of it (alternate dimension? Please), but somehow everyone's more concerned with themselves and their loves lives. Okay, fine; this is emotional, and we're all in this together. But by the time we come across Sebastian, I was ready for it to be over already. 
 I feared for this book because it's the end, and people will die. That's inevitable. They're shadowhunters. But I didn't care about any of the characters who died. (view spoiler)[Killing off minor characters doesn't cut it. Why didn't anyone in the main cast die? And why were they all paired off and in love with one another? Gag me. (hide spoiler)] 
 I wanted a satisfying conclusion, but I'm just indifferent to this whole thing. The best part of this book was Brother Zachariah, who I have an obvious soft spot for. 
 More spoilers: 
 (view spoiler)[ And to have a wedding in the epilogue? What a cop-out for an actual ending. Everything is new and happy and everyone is in love! Where's my angst? And why did Simon come back? That was my last resort for everything not being okay. 
 And what was up with Jace and Clary having sex in the demon realm? That's creepy. Personally, I wanted her to get pregnant and bear a fucked-up kid (for being conceived in a demon realm) and then have to live the whole Sebastian thing all over again. Dude. You don't have sex for the first time in a demon realm, even if you think your life is over. This is not romantic. And why didn't they ever tell anyone else about the fresh water? 
 (hide spoiler)] 
 Okay... I'm done now.