Herthew learned that there was a place of gloom, where the air was foul, and malodorous breezes carried pestilence and poisonous particles. This was the source of all maladies and ailments and of the things which cause putrefaction and decay. This place had been closed off from Earth, for it existed in another realm beyond the ken of mortals; but it had been brought into attunement with Earth when a forbidden act was accomplished. Thus, the bodies of mortals became susceptible to influences from the baleful place.
The Kolbrin, Book of Creation (CRT:7:3)