Nearby the village is a large lake said by the villagers to contain a water god. They tell the party that if they want good luck on their journey they should hire a boat and go to the center of the lake and give a donation to the god.
A long forgotten and abandoned mine has been recently rediscovered by a local village.
When you sleep, your soul briefly returns to the place where it was created/goes to when it dies, and seeks nourishment. Everybody's soul is created with a little link (or you could say a greater entity calls it back) to that place so that it can return easily, but upon death, the soul returns via that and annihilates the link as if returns.
Also, as an added thingy, you could say the entity supplying the link, or residue of the links themselves, (whichever) is the source of all arcane power.