“ A dark necromancer has discovered a way of making the magical energy cost of resurrection less than the energy he can gain by draining their life force. Given a sufficient supply of mind-drained minions, ultimate power beckons.”
“ The player characters, experienced and somewhat well known, hear rumors and travelers' tales about a distant area being overrun by dragons (or other terrifying monstrosities). The locals have sent them a message, begging for heroic aid.
When they investigate, they discover that nothing of the sort is going on. It turns out that a group of thieves wanted them out of the way so that they could rob them (or someone who would normally receive their protection).”