From 11:00PM PDT on Friday, July 1 until 5:00AM PDT on Saturday, July 2, the Shmoop engineering elves will be making tweaks and improvements to the site. That means Shmoop will be unavailable for use during that time. Thanks for your patience!
Magnus reveals that Jocelyn brought Clary to him when she (Clary) was two years old. He's been blocking her Sight every two years since then, making sure that she couldn't see any aspect of the Shadow World.
That explains why Clary couldn't see the scars on her mother's arms and back: they're Covenant Marks, and they were hidden from her view.
Unfortunately, Magnus can't remove the spell without risking permanent mind damage.
What he can do, though, is try to teach her a variety of magic runes.
"Will it hurt?" (13.41) Clary asks. "All knowledge hurts," (13.42) responds Magnus. Except Shmoop knowledge, that is.
So Clary hits the books—the magic books.
The first rune she studies is "something like a winged spiral […] and then it seemed like a staff wound around with vines." (13.42) A caduceus, perhaps?
If you need to do some magic studying of your own, head over to our "Symbols, Imagery, Allegory" section for a moment. We'll keep memorizing runes while we wait.
Back? Well you missed Magnus talking about the Mortal Instruments. Sorry to do this to you, but back over to the "Symbols" page for the details. We don't want his exposition to bog down the plot.
Let's fast forward a bit: blah blah Valentine, blah blah revenge, blah blah Simon's a rat.
Wait—what?! Simon's a rat. Rewind!
Looks like while they were all blabbing on about cups and swords and the fate of the world, Simon drank some blue drink and turned into a rat. Why do they even serve those drinks? Was Anjelica Huston circa 1990 the bartender?
Clary gets mad at everyone. But she's especially angry with Isabelle for letting it happen.
She finds Simon pretty quickly though, under the bar, and tucks him into one of her backpack's pockets.
With Simon secure, they decide to ditch this party. Before shutting the door behind them, Magnus gives them two things to chew on.
(1) He gives Alec a flirtatious wink and asks for him to give him a call sometime. Aww.
(2) He tells Clary that when her mother ran away from the Shadowhunters and their lifestyle, "It wasn't the monsters she was hiding from. Not the warlocks, the wolf-men, the Fair Folk, not even the demons themselves. It was them. It was the Shadowhunters" (13.165).
Well that's new.
Before Clary has much time to ponder that little morsel, she realizes that Simon is missing from her backpack. Someone totally swiped her rat bestie. Uh oh.
They all march back up the stairs to see if Magnus knows where Simon might have scampered off to.
Magnus's theory is that a group of vampires must have taken him, probably thinking that killing a Shadowhunter's pet would be a great way to get revenge for a busted bike.
Their lair is in the Hotel Dumort uptown, so Jace and Clary decide to swing by the nearest Catholic Church (for weapons, of course) before heading there.