PCs have a tendency to take things head on. They also have a tendency to set ablaze, shoot, explode, or hack apart anything that gets in their way. Hint at a corruption plot and a PC will probably punch the corrupt person in the face until the truth comes out and that can make things very hard on the poor GM. Especially when the PCs roll like crazy in combat (and it always comes down to combat) and just make things even bloodier and more explosive.
That in mind, how do you introduce your long plots so that they stymie even the direct approach? Do you only make certain plot elements available until later? Do you make it so a straight line is actually the longest distance? Do you flat out cheat? Hide clues? What?
I've tried all of the above approaches to varying levels of success, but today I figured it'd be worth polling the rest of you guys - and girls - to see what has worked for you.
Please, (seriously, please) sound off in the comments.