I'm DMing a group of reasonably experienced gamers who haven't played Shadowrun before. Their first job was pretty straight forward, and taught them that bullets hurt. Their second saw them double crossed in a fairly tame manner that didn't cause them too many difficulties. They are thus ready to encounter everything that makes Shadowrun special, hopefully before they get too cocky.

I need suggestions for some spectacularly convoluted way of quintuple crossing them. A plot so cunning you could pin a tail on it and call it a weasel, a storyline more twisted than a /b/tard's mind, a scheme so insidious the players will start mistrusting each other even outside of the game. Help!