Before the Great Diffusion of 1247 GUE, all discs were gathered by the good wizards to be destroyed to smithereens; except one they could not find. The last one, known as "Nectus", was broken into six pieces and hidden by the evil wizards before the good wizards could get a hold of it. Their motive was to find the pieces eventually, reforge the disc, and shatter the Wall of Illusion they had been tricked into believing; concealed all the magic in Zork. The evil wizards also built the Six Ancient Muses of the Arts designed to reforge the disc and restore it into it's original form.
When the Great Diffusion finally took place, the decoy Wall of Illusion shattered, then the evil wizards realized they had been tricked. Fortunately, it is unknown how the Six Ancient Muses of the Arts survived - and although unknown at the time, the pieces of the final disc also survived. Without these, the mysterious Sweepstakes Winner would have never been able to reach Morphius behind the Wall of Illusion by the Cliffs of Depression; that concealed the Citadel of Zork!