I was at a school for magic, although nothing so charming and supportive as Hogwarts. I got the impression it was rather cutthroat. Students were expected to choose one of a number of color-coded books of magic to learn from--the Red Book, the Green Book, whatever--which covered the branch of magic you went into.
Somehow or other, I and a few friends (roommates? Co-ed, if so...) had found a great deal of old jewelry, all of it in the shape of tiny clockwork animals. The jewelry actually turned you into the clockwork animal in question. (I was a red iron clockwork horse for awhile, which was pretty cool.) The problem was that one of our buddies had located only one of a pair of earrings, which turned him into a very tiny clockwork fox, but without the other earring, he couldn't turn back. As these were very small studs, we were scouring the castle (there's always a castle...) trying to locate the other stud, without letting anybody know that our buddy was off somewhere in clockwork form. Since the whole hoard had been lost for centuries, we weren't having much luck.
Unfortunately, by using the jewelry, we'd accidentally kicked off some sort of Bad Chain of Events, and various harbingers were descending, in the form of strange black birds with big eyes and fluorescent green crests. One of my roommates got the story about what the jewelry was from a grim woman obsessed with magical jewelry, who was supposed to be her therapist/keeper/etc. Unfortunately, I don't remember much about that bit, other than the being lost for centuries thing.
Never did find our clockwork fox friend, but oh well. Neat visuals, anyway.