So I'm trying to set up this fantasy story... In the first couple of chapters there is a war, and the leader of "the bad guys" (if I may simplify it) is crawling into some tunnel under a small castle and sort of "locks" the hideout or just closes it and makes sure it's well hidden. I need to think of something that on one hand would be a sure way to hide (after all, he has been planning it for a while) but on the other hand, would be found quickly (I need the good guys who are roaming through the castle, looking for him, to find him rather in a hurry and storm the tunnel. There is another plot line, with other characters, that involve a person trying to get the old blueprints to a city. I suppose that the blue prints, made by an architect who is long gone, can also include the surprising blueprint of the castle. I need the places of the two plot lines to be far from one another, in either different times or different places in the world, because the first plot line happens in the snowy winter and the second one in the summer. And I don't wanna rip off George R. R. Martin. (If you want to reference Martin, please no spoilers. I'm still in book 1. Please no spoilers). It's a world that has griffins and dragons, so I suppose the blueprints can be flown from point A to point B. Still brainstorming it with myself.