An explorer gone missing. A king in panic. A treasure to find.
Welcome to the Craggy Peaks. We hope you don't freeze to death.
That would mean we couldn't... play.
A town is besieged by a changing culture and is desperate to hold on to its oldways. But that gets harder as the next generation starts to leave the traditions behind. The drive of some people to resist change and hold on to what they have is so great that they will not only fightthe undead but eventually embrace them.
An elder cleric asks the PCs to transport a relic to a nearby city. A simple quest with endless possibilities.
A secret MLM (pyramid) company that offers eternal life, but in fact it transfers the life forces of its members to those position "above". If you get high enough, (meaning you get enough new members) you start to enjoy the benefits. Maybe a willing sacrifice is much more effective for the transfer. But no one says, that a suddenly unwilling member, threatening to tell the authorities, may not loose it involuntarily... thus start people to vanish, and aged corpses are deposited somewhere safe.