Escape Plan Riddle

You’re trapped in a room with two doors. One door leads to freedom, and the other leads to certain death. Each door is guarded by a man. One of the men always tells the truth, and the other always lies, but you don’t know which is which. You can only ask one question to determine which door leads to freedom. What do you ask?

You ask either guard, “If I were to ask the other guard which door leads to freedom, what would he say?” Then, you take the opposite door. The truthful guard will point to the wrong door (because the other would lie), and the liar would also point to the wrong door (because the truthful guard would tell the truth).