The once great port city of Calimport lies in ruins, the very ground it sat on being rent asunder. In the ruins the revolting population still battles the forces of the Grand Vizier, but it is a losing battle. Even fragmented and without command the vampiric forces command powers far beyond mortal ken. In all the chaos many thousands of slaves and other refugees seek to escape the city in the hopes of finding safety elsewhere.
It is into this destruction that you have emerged, climbing out of one of the many rifts.

You have just defeated the avatar of Shar, blasting her with the raw power of a dying god of magic before impaling her with the Black Knife. Thus ruining her plans to fully manifest in the material plane the ritual failed in a catastrophic manner. The weave, already strained from Mystra’s condition and the Wizard Wars in the East, collapsed. An eternity passed in the blink of an eye as reality shuddered, collapsed, and reasserted itself. As you recovered you were surprised to find magic still had power, it felt different, a shadow of its former self and not like the weave of old. It was clear the world had changed, in what way you have yet to discover.

An Age of Darkness