The demon laughs. "Indeed. Very well. Go through the door. Hades is a puzzle box, a fivefold lock, and it requires a multitude of keys, keys of words and keys of blood and the flavour of your soul. Something you have, something you know, something you are, and these latter two must be proven twice, so that five proofs unlock the Pentemychos. Each layer of guardianship has its price: Cocytus, Styx, Lethe, Acheron and Phlegethon. You must cross the five rivers of Hades and do your will in the place set aside for you."