It wasn’t the Tarrasque that was so dangerous; it was what the beast heralded. And it wasn’t the heroes who would stop the darkness from returning; it was what they held collectively in their souls. The great beast, released from time to time throughout history by foolish summoners and those with malign intent and the false conviction that they could control such a primordial force of destruction, would bring about the release of something far worse. The Hags, indeed, wanted to see the age of man come to an end, and believed that the Tarrasque would, if summoned properly, destroy the kingdoms of the civilized races, and along with them manifold protections against the release of the Hags’ demonkin. Once spent in its mission to destroy the Daughters’ enemies, the beast would be easily placed back in its storage box by the leaders of the new order, some fully free of the Demon Wastes and others provided easy access to Khorvaire through extra-dimensional portals. The Hags would have their new order, and the civilized races would be broken and forever subjugated.
What the Hags, in their narrow-minded arrogance, did not realize is that the Tarrasque was always only the beginning of a series of events that could not be fully foretold, to say nothing of controlled. The beast, simply put, was the footman to the worst evil imaginable: the source of evil itself: the deathless Khyber. Additionally, in their single-minded pursuit of the means of its release, they did not realize that another event was inextricably tied to it: the return of Eberron, the great dragon that had, in the mists of time before time, smote evil Khyber to avenge Siberys’ death. The world-as-known would end – in this the Mosaic Chamber were correct – and in its place would come another reality.
The heroes, for their part, were vessels for the core elements of Eberron, which could only be themselves released and reunited under special circumstances – specifically, the arrival of the Tarrasque. When the great herald of destruction, which threatened to free the deathless dragon Khyber and sunder the world, arrived, Eberron would be there to meet, and best, it. The heroes, drawn to the Prophecy, enlightened by the Prophecy, and ultimately agents of it, brought themselves forward to the brink, where one reality would end and one of two others would begin: one light, one dark. Their sacrifice was the last step that enabled Eberron to prevail, and the next world to exist in the light. Khyber was held in check – ever-present and scheming, yet held – as Eberron wiped away the stain of the Daelkyr, Quori, and forever rewrote the story of the stars, precluding future cosmic combinations that would open many doorways into this world from others. A new world was created, and on it would grow up the races, in new lands and kingdoms.
And over the surface of the new world glided a mist, invisible to all but a few, and this mist carried in it the essence of creation, left by Eberron’s work.