The Sundering was a major event that shattered the entire Multiverse. Highemperor had been manipulating the Story so that he would become the sole user of the fabled bloodink, essentially linking himself to the Story's narrative and controlling it. However the vampires that were working for him betrayed him and managed to weaken him. This then caused the Story to distort and shatter. Eventually he was able to use his Powerplaying to restore the fragmented Multiverse back together but two new planes came to be as a result. NeShattered was formed, an alternate reality of the NeS that is twisted and corrupted. However there also existed The Fracture, a plane of existence where pieces of the Multiverse still reside that were unable to return to their original positions in reality.
Tales from The Imperium
Reality is like a china teacup, once shattered it can never be fully restored to its perfect condition; cracks exist and tiny fragments will be missing. Those fragments of reality became stored on what would be known as The Fracture. The Fracture came into being after Highemperor restored reality with his Powerplaying and this new plane, beyond reality, would be discovered by The Imperium. The Imperium chose to then use The Fracture as the headquarters of The Peacekeepers, who could get in and out of reality easily from there. The fragments themselves, numbering in the billions, come from across the Multiverse and exist within The Fracture as floating islands of all shapes, sizes, weather patterns and even physics. Once it came into being, the majority of beings in the Multiverse forgot it ever happened, from men to gods, and explained the missing structures by other logical means. Such fragments include The Heart of Yself and Castle Camelot[Tales 1].