I know that this type of question has been absolutely done to death (where did that expression come from anyway?) but I have a premise for a science fantasy story. I have a skeleton of an Idea of what the story will be, but here's what I have so far. Time: unspecified. Disaster: sometime in the distant past, a disaster the likes of which hadn't been seen since the biblical day's of old was swiftly falling upon the land. Somewhere in in the middle of the pacific ocean, a poisonous green fog begins to seep off of an unremarkable island, volcanic in origin, about a square mile in size. This wouldn't have been a problem, since such a small amount of fog would have eventually lost itself in the vastness of the planets atmosphere, and the stuff it was made of was largely biodegradable through a variety of ways found in nature. So it was sensationalized for a while, with the usual kerfluffle, and then it was quietly forgotten as some new crisis arose, banished to the shady corners of science, with only the ocassional visit from some obscure science foundation sponsored trip. And that was that. That is, until, somebody noticed it was growing. And sure enough, it seemed that, contrary to what the specialists said, it was slowly, steadily, patiently growing, getting thicker and thicker. Eventually, (about four years) an expedition was chartered to go into the now opaque cloud. Here is one adventurers account of what it was like. " After a looong and boring flight, we neared the destination. Looking out, all I could see was what looked like a big greenish-brown mound. the truly weird thing about it was that it's edges weren't very well defined and looked like what you would expect something like a giant cloud of steam would look like that was left to dissipate, but there was a definite edge to it that billowed like a great sheet of canvas in the wind" Note: this is not the end of the story and setting, just my present atention span. I promise to include more of the setting and premise in the comments, but for now i'm completely fried.