It took great effort, but Severus valiantly refrained from making a scathing comment about stating the obvious in response to Black, but as difficult as it was, he knew he ought not risk derailing the meeting with a quarrel. At least not so soon. He really wasn't so sure how long he would be able to hold out if Potter and Black kept making such asinine remarks. Instead, he forced himself to focus on the matter at hand.
"It seems to me that we should concern ourselves less with what is happening and more with who is causing it. No matter what the source of the problem is - spell, ritual, or artifact - it would have to be activated by a mortal agent. Who would gain by causing this kind of damage and chaos among the Wizarding community? The list of suspects is quite short, I imagine. Find the culprit, and no doubt we will find the source of this ever-growing problem and thus be able to put a stop to it. Perhaps we can succeed in that respect," he added with a pointed look at Moody, who glared back balefully.