It begins after the Hittite prince, Zannanza, was assassinated on the way to Egypt.
Dismissing the protestations of innocence from the new pharaoh Ay, a bereaved and angry Suppiluliuma immediately took punitive action, sending Hittite troops into the Egyptian-held territories. Ironically, the Egyptian prisoners whom they transported back to Hattis from these campaigns were blamed for the pagues that wreaked havoc in the Hittite heartland for the next two decades. Six years after his conquest of Karkamis, Suppiluliuma died, probably from this very plague. His son and successor, Arnuwanda II, also succumbed to it after little more than a year on the throne.
(Billie Jean Collins, The Hittites and Their World [Atlanta: Society of Biblical Literature, 2007], 49.)It continued to be a problem for Suppiluliuma's successor, Mursili:
The plague that Suppiluliuma had brough home from his conquests in Syria continued to rage unabated throughout the kingdom well into the latter half of Mursili's reign. There was no question that this scourge had been brought on by an angry deity, but Mursili had to find the source of its anger. Oracular inquiry identified three possible causes, each attributable to Suppiluliuma. Among the possibilities was a retaliatory attack Suppiluliuma had made on Egyptian-held Amka, which, it turned out, was a violation of an old treaty between Hatti and Egypt. Wile maintaining that the responsibility for the plague did not rest with him personally, Musili promptly made restitution for his father's lapses.
(Collins, The Hittites and Their World, 51-52.)Here's hoping the current plague does not last two decades.
