Crackplot
Jaenelle is housecleaning. Clearing out old spells, discarding old tangled webs, cleaning the cobwebs out of the spells she's maintaining in both her study and her room. However, that volume of magic from Jaenelle is almost guaranteed to leak. So, floating around the Mansion are little wisps of Ebony mist that most people probably can't see, just floating around until someone walks through it and breathes it in - in which case it will promptly (and painlessly) purge all the spells out of a person. A light breath might just get rid of a few, whereas several will get rid of all of them - excepting, of course, the magic of the Mansion, like the translator. (We just had that one, after all.)