In one game I was playing, I suppose we missed the hooks that the GM wanted us to get, 'cause there was an earthquake, and our entire party fell in to the fault. So we wake up, and we're lucky to have gotten away with a few broken bones. Fortunately we had a magician, because none of the cleric's spells seemed to work. Then we find out it wasn't an ordinary fault or earthquake. No, we fell through a portal to the plane of demons, and almost literally on top of a group of the buggers. The Queen of Demons, who of course had the equivalent of a magic mirror, wasn't exactly pleased. So between avoiding the demon army, and trying to keep a pair of succubi away from the males in the group, we had a pretty long haul to get out of there. THAT is what I call a dirty trick.