If anyone is interested, here is the adventure (in pamphlet form) I ran for my group loer our third session. It served as a bridge between A Stranger Storm and Death Frost Doom.
Here’s the basic setup:
a small village in 17th-Century Bavaria. Meteorite landed somewhere nearby four days earlier.
The day after the meteorites landed, eight villagers went off to investigate. They found the steaming, cracked remains of spherical meteorites that appeared to have been hallow.
The meteorites carried Changelings that can mimic the appearance, clothes, and thought of anyone they see. But worse, the radiation from the meteorites mutates humans.
Not only did the Changelings follow them back, but the eight villagers were doomed, transforming and becoming servants of the alien intelligence that launched the expedition to Earth from Carcosa. Most of the men are already dead by the time the PCs arrive, killed by friends and family or by their own hand.
When the Player Characters arrive in the village under a rain that never seems to end, looking for information about the meteorites, the windows will be shuttered, the doors locked. The surviving villagers retreated into their homes two days earlier, uncertain what to believe and who to trust.
Two monstrous mutations will be at work in a village house, translating data back to Carcosa. And it is here that the PCs can learn more about what interests those who launched the expedition:
1) The location of a fallen shrine of a death cult that battled Carcosa’s Old Gods thousand of years ago.
2) The recent revival of an Insect God’s cult in norther Bavaria.
The PCs are caught up in a long-standing conflict between the Sorcerers of Carcosa and the Duvan’Ku cultists of Death Frost Doom.
The Changelings in A Stranger Storm were sent to Earth in meteorites by magical means to provoke reactions from humans. The gems in their hearts collect the emotional data and transmit back to Carcosa via the pond outside of Middlehelm.
Meanwhile, the radiation of the meteorites mutated several citizens of Middlehelm and turned them into servants manipulated from Carcosa. Chaos ensues.
The PCs don’t really know anything about Carcosa yet and only started piecing bits of facts and history of the Duvan’Ku after traveling toward the “Death” symbol the found marked on the inside of the knight’s flesh in the adventure below.
These are my notes. Not an edited, publication ready product or anything.