Has it not occurred to anyone that Sigdi might well have known of the prophecy, even many years before the High Priest's shenanigans?

Suppose she knew more:

1) She could prepare for it.
2) She might even impoverish herself to prepare for it.
3) She might even raise her son in such a manner to mitigate his ability to carry it out.

Durkon is supposed to bring death and destruction to them all, but nobody said how. Perhaps Sigdi knew, or had more clues.

Honestly, it looks like Kudzu is a far greater danger than a handfull of vampires. Once exposed, vampires are a pain, but they are killable. They might be the dearh for all in the prophecy, but I find this a very minor provocation in the grand scheme of things.

But what happens to dwarven society in the face of a dwarven high priest of Loki who provides an out for the dwarves who are not fond of Thor, who is only the better of the two allowed choices? Kudzu is dangerous, and he's only where he is because of Durkon.

Perhaps this is why Durkon's mother trained him to suppress his romantic urges in favor of his duty.

Whatever is in the back room, I'm betting it's Sigdi's answer to the prophecy of Durkon.