Chronicles of Khaldun: Crux of Eternity
A Convergence is a weak spot where the planes bleed together. They occur with some frequency throughout the Sorrowfell Planes, and although they appear to be a naturally-occurring phenomenon, most sources only record Convergences going back two hundred years or so.
Some doomsayers claim that the proliferation of Convergences proves the end of the world is nigh. Especially since monsters and travelers may occasionally utilize the breach, possibly to the detriment of all involved.