"In a primitive sense," he agreed a bit begrudgingly, sitting beside him on the bed. His room may not have been elaborate, but the bed was more than big enough for two to sleep comfortably. Or not sleep. "And you've already seen the cleansing charm. Because I actually have common sense, the first thing I'm going to teach you is a counterspell. It'll end any spell you cast, and all sorts of simple spell cast by others. The incantation is 'finite incantem."