Dumbledore's Army Sign-Up Sheet
Brilliant Hog's Head Pub
Hog's Head Inn, Hogsmeade
This parchment, while a seemingly innocuous non-disclosure agreement, hides a clever trick. Unbeknownst to the members of Dumbledore's Army, Hermione Granger jinxed it so that anyone who signed it and reported the group to Dolores Umbridge would have the word ‘SNEAK’ appear on their face in boils.