It sounds like you may be in trouble. I wish I knew what to tell you, but if you don't have the serpent's key any more, and you haven't got the serpent's idol yet, you may be screwed. If you want, I will send you a save game where I have everything, and am standing right in front of the altar ready to perform the ceremony, but I'm not sure how or even if you can get the items over to your characters. Just let me know if you want it. My email is
spookyron1@earthlink.net