I would rather occasionally count down out loud (Thereby warning the players of impending doom) than tell the PLAYERS that the PC's were just stabbed in the back while the PLAYERS were discussing the battle plan (Or lack thereof)
I think its the right thing to do.
Sometimes.
On the other hand, sometimes the NPC's just wanna have fun......... :
and what could be more fun than eliminating those always pesky treasure thieving PC's?
