"The same goes for our magic." He began to dig around in one of the bags. "There's next to nothing that's absolutely permanent." He came up with a scroll case, popped it open, and unfurled the scroll, holding it out to them. In anticipation of such explanations, as well as for his own benefit, he'd copied down the exact properties (http://www.d20srd.org/srd/spells/balefulPolymorph.htm) on the back. "This one's one of the strongest I brought, but it can still be dispelled."