Odhanan said:
Well, I really like the adventure that goes with a first part of investigation, finding out what the killings are about, facing the serial killer, and then realizing the serial killer is part of a bigger problem, and top it by a second part that is the "strangers in a dungeon" scheme.
i would do the opposite. starting with the "strangers". then they get to the surface of the world. then billir dies. then they start investigating and they discover the workings of the chaos cult.
the only problem with getting so many things together, though, is that at some point you will either need to "throw away" some work (because the players choose another path), or railroad them into the adventures you have planned.
#1 and #5 work relatively well together because #1 has defined opening themes (the mystery around what has happened, the exploration of the dungeon) but leaves what happens outside really open.
#5's key elements are really just the killing of a friend and a chaos cult. you can incorporate those elements in whatever plan the PCs have (want to stay there and help the community? destroy the cult. want to return home? maybe the arcane tomes in the cult's temple will help you to open a portal. want to fight the lich, or Wurd? simply connect the cult to them...).
similarly, i could connect some *elements* of other campaigns together: why the orcs are ramming at the door of the chamber where the PCs are? why are they running rapage in that level of the dungeon? why they seem to be fighting for their lives?
simple: there is a problem with zombies in the upper level, the level they used to live in, and it is slowly spreading down there, too. it would connect the spirit animated zombies with some ancient cave or chamber that the orcs have "soiled" with their presence.
in that case, though, the antartica theme might be dropped; the scientific approach to the problem *will* be dropped, too; the magnitude of the event might be turned down, too, with the zombies becoming easier to kill.
you get the picture.
Odhanan said:
WOW. The idea suddenly becomes a LOT more interesting. Nice touch! Could work great in the Wilderlands of High Fantasy too.
glad you liked it!

the way i would execute all of the campaigns above would accentuate the grittiness. think old school or hard boiled/ spy story (for the #2). i think the peasant idea is the only one having a touch of light heartedness in it, mostly because i conceive it for an OD&D campaign in Mystara for a group of younger players (whose "seriousness" i couldn't be sure of).