[andrewas]

Game Critical items (like the eye-stalk) do not decay from the game world, since this could lead to the game becoming uncompletable. items that you can finish the game without decay after 24hrs (plus a random amount). therefore the blade is gone, vanished, out of there.

either load an old save, hack it in, or live without it. if it helps, its not that awesome of a weapon anyway.