Taylor: "Wait, there's a curse on the Defense Against the Dark Arts position?"
McGonagall: "That there is, Mrs. Potter, assuming the results are to be believed. I have no idea how such could be accomplished, however, nor have I seen any direct evidence such as runes carved into the walls and whatnot, nor is it tied to a specific classroom, as we have moved it several times thus far."
Taylor: "And none of the other teaching positions or classes are affected?"
McGonagall: "Correct."
Taylor: "Then end the Defense Against the Dark Arts class entirely, open a couple of new classes in two separate rooms that have never been used by a D.A.D.A. teacher, and split the Defense class into two courses: 'Practical Magical Self-Defense' and 'Defense Against Magical Critters," each run by a different teacher. No more Defense Against the Dark Arts, no more problems."
McGonagall: "...Oh. Oh dear. This is unprecedented. I've never seen this before!"
Harry: "What? What is it?"
McGonagall: "Is this what they call 'common sense'?"
Taylor: "Not common at all, I've found."