I'm playing the 1st run of the "Age of Worms" path and...
... one of the quests is: "return my remains to my family's farm and bury them next to my kin"
... the initial task sounds easy enough, but, as always, it keeps getting complicated. Personally, i like that... (i won't go into more spoiler stuff)
Start off slow and with a bunch of clichés (i.e. major hints to what the players are supposed to do), like:
"Dying traveler on the road: Carry this family ring/letter/ to my family, please... Aaaaaaaaaagh..."
They get there and most of the family is already dead from a disease or something... Only a younger brother survived and he became a bit bitter and reclusive after that. He survives by selling old trinkets and objects in town from time to time, so he's probably a spelunker of some sort. However, nobody has seen him for weeks. The best guess is that he's probably digging around some old caves and ruins near town.
The PCs get to the caves/ruins and they've been settled by goblins or a religious death-dealing cult or whatnot...
Feel free to expand from here. The brother may be a captive or a survivor, who ended up having his exit cut off by the goblin incursion...
The PCs will feel the need to get him out of there and return him safe and sound to his home.
You could then elaborate even further, by having the goblin or cult incursion part of a bigger plan of an unknown entity, into which the PCs happened to trip on...