The plague crawled into the Old Kingdom on the backs of packhorses which came with infected goods from over the mountains. With the first deaths came uncertainty, then fear, and a stunned horror as the mounting tithe of life reached into the thousands. Panicking people fled, flooding the passes with rank upon file of refugees. Neighbouring kingdoms, afraid for their health, quarantined these migrants, sending back hundreds to die in their own country.
The soothsayers prophesied it would be more than four-hundred years before the the Old Kingdom would be safe to visit again, so persistent was the plague. For a long time the neighbouring kingdoms posted sentinels along their borders with the Old Kingdom to stop anyone entering or leaving it. After a while, there seemed to be no-one trying to leave. They must have died out.
King Mak of Sospiria was the first to ignore the soothsayers. His greed had the better of his rationality, for when that sickly realm was abandoned, so with it were the treasures of its inhabitants. Churches and castles rich with gilded paintings and statues, left to crumble and rot, guardianless. After only a hundred years, Mak sent a troupe of looters to find what they could and bring it back to him. Of course on their return they bore the symptoms, the oozing wounds and perished muscles, that characterised the plague, and they were turned away by their repentant King.
Since then none have dared risk the same terrible fate, or if they have they have been silently slain by the sentinels as they tried to return.
Meanwhile in the Old Kingdom, not all those who had the plague died. There were some with natural resistance. They and their offspring still live on in the towns and cities once inhabited by thousands, now neglected and in ruins. They are assailed by the beasts and trolls of the surrounding mountains and have become a hostile race of warriors. Some towns, like Calanz, are completely overrun.