I knew right away that I wanted a contiguous campaign of one apocalyptic event after another, using each of the four books to create one apocalyptic campaign.
Overplanning is a weakness of mine.
So, the zombie apocalypse would be the precursor to the Wrath of the Gods, where the robots used to contain the last of the zombies would then have to do combat with legions of whatever deities are involved, leading to the alien invasion and the subsequent robot uprising. THose robots are really going to betray us. But we all knew that at the start.
But when I explained the broad idea to a friend, he suggested that I use all of the Scenarios in each book.
This is the current order I plan to run those Scenarios as events:
It Ends with a Whisper. This is where it will start on a small scale in a few places where Hollywood says voodoo is practiced. The characters (who will be make believe, not interpretations of the players) will be in one of these locations and will have a big one-shot adventure where they will learn the secrets of the voodoo priestess and why she is so successful. And then, possibly, defeat her.
The secrets of her mojo juice that can reanimate the dead will be found in an artifact that seems to have resurrected some form of disease and spread the Pandemic as soon as it is brought back to civilization. This is where the world becomes less recognizable.
When a meteor storm, perhaps not as natural as we assume, takes place, a new form of weird zombie shows up. They are different than the others, and as the meteors continue to rain down on out home world, the charters will have to identify and combat the varied forms of undead.
The weird, reanimating force (radiation, mutagen, whatever soft science the players will swallow) combines with the viral form of the zombie disease and Under the Skin makes an appearance.
The solutions will be up to the players and their character's actions. Once they have begun to get everything under control and get a rare glimpse of hope, they discover that there is…
No Room in Hell. This is the beginning of the Wrath of the Gods and will further disguise that transition.
The world will be royally screwed for the new gods to whip back into shape.
When does that next book come out?