The God-Breaker Plague is a curse that affected ancient Egypt, in which all supernatural creatures were rendered mortal. They lived the rest of their lives this way, and died within a generation. The plague is said to still dwell in the Valley of the Kings.
In Timeless, it is revealed that the God-Breaker Plague is caused by the mummified bodies of preternaturals. The plague was started by Matakara to eliminate werewolves, possibly at the behest of the Greek ruler Alexander. The last report of the expanse of the God-Breaker Plague was made in 1824. Beginning in 1841, Alessandro Tarabotti began the expansion of the area affected by the God-Breaker Plague. After his death, it was further expanded on his orders, carried out by his loyal followers and Floote.
The plague's epicenter is near Luxor, at a prominent bend in the Nile. This is the site of the funerary temple of Pharoah Hatshepsut (aka, Matakara).