Here's a hypothetical problem : suppose your most faithful partner - called Robin - got kidnapped by the Greatest Crime Genius - called Nygma. Suppose that after a fierce chase, you finally find Nygma's lair, a big underground shed supported by nine pillars, each with a door and a plaque.
 Nygma's voice rises to welcome you, and explains that in each pillar is a room with an airtight roof compartment. It can be opened by pressing a button at the end of the room, but the resulting effect depends on the plaque at the door.
 If Robin, who's suffocating, happens to be in the compartment you're opening, the inscription tells the truth. If it hides a giant piston which will crush everything in the room, it lies. And, last possibility, if it's empty, the button will open a trap door which leads to an underground prison, and the inscription can tell the truth or lie.
 If you're smarter than it seems, you will shortly cry :
 "Riddler ! This problem can't be solved ! - Actually, I never said it could be, Batman ! - What about our battle of wits ? Do you want to win by cheating ? - All right. I'll allow you to ask one question, answerable by yes or no... - Is room #8 compartment empty ? - Hmm... Let's say that if I answered to this one, you'd be able to find Robin."
 Which door would you choose ? Despite what it seems, I did give enough clues to Batman for him to solve the Riddle. The Maze above is interactive (only if you have Flash player, that is). Think up, and click on the pillar # you think is the right one to see if you've found Robin, an empty compartment, or sudden death.