Magnus/Alec. Familiar faces from The Mortal Instruments begin their formal education at The Institute. Even snark can't hide the fact that it's one scary place. Imagine HP meets TMI, with more sarcasm.
Jace/Alec, Magnus/Alec, Jace/Clary. Story begins after the cookie for City of Glass where Jace dares Alec to kiss him. What will happen to their relationships, both with each other, and with those they care about, if Alec does?