Once the axe called Death Bringer was stolen from its temple, and given to the Cult of Death, the machinations of the old gods could finally be realized. The cults extracted the old god souls that were in the axe, allowing aspects of their darkness to flood into the realm of Midgard. The hour of vengeance was nigh. The aspects possessed the Cultists, allowing for real work to be done.
The old ones set to work, resurrected the dead that lay beneath the earth, setting them to the task of stripping the life of any who turned their backs on them. For, even though many of the Clan Daupuz considered themselves worshippers of the old gods, they had long forsaken the old ways for more than tradition. They did not seek out the old gods, nor sacrifice to them.
The new gods could not protect Midgard either, for the old ones had had much time to plot, and constructed a dome of malicious energy to seal their fjord in. If Heimdall, Thor, or even Odin himself tried to cross into the dome, they would become near mortal.
Clan Daupuz was left on its own and had to flee from the dead to an island within the dome, but the task for restoring the realm and beating back the darkness fell to mortals.