"What can you do when your players are about to do something astoundingly dumb because they aren’t thinking things through? There are many possible solutions.
Use an NPC to nudge the players in the right direction.
Give the players hints out-of-character.
Allow them to do the stupid thing, then laugh at them later.
Find smarter players.
#4 is obviously the wrong answer. Having players smart enough to outwit you is a tremendous pain in the backside. Don’t make that mistake." ~Shamus