...chosen to explore this relation of world to shadow, Azra was the first to realize that shadows were not a mere absence of light, but a reflection of possible worlds created by forces in conflict. A light strikes a rock, and the shadow is a record of their clash, past, present and future. Other conflicting forces produced less obvious shadows, fire and water, wind and rock, or nations at war. With skill and patience the shadows of all could be read, and patterns teased out, emphasized or eradicated. Manipulating a shadow could, through contagion, manipulate the object or force which cast it. Azra was eminent master of this nearly imperceptible magic.
...Azra attempted what had never been done before, manipulating his own shadow to such and extent that he instantiated and melded all possible Azras at the same time, crossing over from this singular existences in shadow. Ignorant Redguard soldier, fearing the power of Azra should he succeed, trapped and confronted Azra. The battle did not go well for the wizard. The hole blasted when he lost control of his magics can still be seen at the village that bears his name, Azra's Crossing. The science of shadow lost a great man that day, although others, such as Pergan Asuul, strive to take his place. - http://www.imperial-library.info/skbooks.shtml
It's a bit like the http://en.wikipedia.org/wiki/Many-worlds_interpretation, all possible worlds are put back together again and then you pick an alternate line for the thing you want to change.