Harry Potter & The Other Realm

An illegal connection to the Other Realm Transport Closet Network ditches sixteen-year-old (and newly-revealed-to-be-a-witch-and-not-yet-anywhere-near-in-control-of-her-powers) Sabrina Spellman at Hogwarts. The meeting of two very different magical worlds doesn't go as smoothly as one might expect. For one, Snape is turned into a pineapple.

After their run in with a very strange muggle-clothes-wearing blonde with no shoes, a black cat and being chased by Snape, Harry and Ron decide that (unlike every other year) something strange is going on. Of course, instead of going to teachers who would be able to protect the school from dangers and suchlike (allegedly), they go to the one person they know, who knows stuff.

Sabrina's on the run. Salem is being his usual smart-arse self. Snape is on the rampage. Several sentences beginning with 'S'. Harry, Ron and Hermione are left to come to the rescue and Salem has an encounter of the feline variety, when he and Sabrina get separated. *snickers*