The trapdoor in the Church Ruins lead to the basement.
The church basement is a bloody place full of bodies lying in improvised beds, if the player steps in one body he will be poisoned, the place seems to be a improvised hospital where the doctor tried to stop the plague.
The choice of the player in the dream (fight with the black chomper, or flee through the window) changes the enemies inside this place, if the player kills the black chomper and open the trapdoor (ending the dream) Huge dogs will roam the place, eating the bodies of chompers, these dogs are less aggressive than usual. And the Distorted Key can be found killing one of the dogs and looting his body in the end of the place.
If the player flees through the window, the basement will be crawling with chompers and the Distorted Key will be found in the end of the place.