We both really enjoyed the movie and we thought we would discuss some differences between the movie and the book. Don't read this if you haven't seen the movie (or read the book) because otherwise we will ruin it for you.
A large portion of the movie followed the book, for the most part. There were minor differences that made sense to us. For example, when they go save Simon from the vampires at the hotel, it's not just Clary and Jace, but also Isabelle and Alec. That makes sense for all of the main characters to be in more scenes. There were other differences that didn't make as much sense. Simon isn't turned into a rat and mistakenly taken by the vampires. They actually target him by spiking his drink and then take him because they're really after Clary and the cup. Why? No clue. (There's also no flying motorcycles, by the way). Also, when they go back to get the card of the cup and the woman is a demon, instead of Simon getting rid of the demon with the bow and arrow (shooting out the skylight to let in the sun), he smacks her with a shovel and then Jace gets rid of the demon (and they don't make it clear that this demon was not killed, just sent back). Why? No clue.
There were other scenes, and even lines, that were straight from the book, which was great to see. Some snarky comments by Jace were almost word for word from the book. And both of us really liked Jamie Campbell Bower, the actor that played Jace, even though we weren't thrilled about him before seeing the movie. Lily Collins also was an excellent Clary.
Now to the big differences that we're curious about affecting the rest of the movies. There's a portal in the Institute, which is how Valentine gets into there, which was completely different from the book, and how Valentine is able to do that is an important part of later books. Clary goes to see Hodge alone in the library with the cup and then Valentine comes through the portal and tells her she is his daughter (which was different from the book). In the book, it's both Clary and Jace, and Valentine takes both the cup and Jace.
In the movie, Clary then puts the cup back into the card (Valentine is trying to get her to drink from it for some reason, after he puts his blood into it) and jumps through the portal, landing right outside of Luke's bookstore. Obviously none of that happens in the book.
So Valentine and Hodge are left at the Institute, with no way of getting the cup out of the card. Then Hodge suggests to Valentine to lie to Clary and Jace that both of them are his children. So then Jace shows up and doesn't recognize Valentine as his father, but he knows that he is Valentine. Completely different from the book. So Valentine does something that wasn't too clear, and he makes Jace suddenly sees his face as his father (remembering the scene with the bird that he gave Jace for his birthday and then killed). So does that mean Valentine didn't really raise Jace? It wasn't clear to us, it seemed as if he just made that up on the spot. If he did raise Jace, why wouldn't Jace remember him as his father, which is what happened in the book?
Meanwhile, Hodge and Valentine let demons into the Institute, and Clary and Luke show up with a bunch of werewolves and they have to fight the demons, along with Isabelle and Simon. And Clary's mom somehow winds up at the Institute. Clary finds Valentine, her mom, and Jace and that's when she finds out that Jace is Valentine's son, her brother. Obviously that is totally different because in the book she knows they are brother and sister before Jace does, but in the movie it is the complete opposite.
Jace and Valentine are fighting, Valentine is about to kill him, and then Clary is holding the cup in the portal, about the drop it. She then gives it to Valentine and then shoves him through the portal. He tries to grab her back, but Jace holds onto her, and then she stabs something through the portal, and then it freezes the portal, and then it bursts. And come to find out, Clary gave Valentine the replica of the cup, not the real one. So obviously that is completely different from the book, where Valentine has the cup and goes through the portal (that is not at the Institute) to Idris.
We left out a lot of what happens, but we thought it was interesting how many changes they made at the very end. Some of it made sense (having all of the action happen at the Institute, and more fights involving more of the characters), but other parts of it, not so much. Still, absolutely loved the movie and we hope they keep making them!
Let us know your thoughts! What did you think of the movie? The differences between the book and the movie? What other differences did you notice?