A deal struck between the Methuselans and the Isys’ir. This ended the Stellar Decay.
Humanity was told to stay out of the Abyssal Realm. Unfortunately, we didn’t understand what that meant at the time and eventually is passed from warning, to legend, to myth, and finally forgotten.
The activities of Samalek and Deitech breached the Abyssal Realm and broke the bargain.