Clues

These are all the clues the players can find in the cabin

1. Near the house they find another corpse
   the guy probably ran away from the cabin and the demon killed it
   When they investigate it, they find a piece of a puzzle (the puzzle to open the sacrifice chamber)

2. When the players come to the cabin, they find a woman hanging from a tree outside
   If they investigate her they find a suicide note. It reads:
   "i can't take it anymore. These voices always drag me back here, wanting me to do horrible things. There is no escape. Maybe in death i will finally be at rest"

3. Inside the cabin there is a suspicious dent in the wall
   after further investigation it turns out the dent is a keyhole

4. The key to the keyhole in the wall is hidden in the cabin in some pots
   as a hint a ghost might rattle the pots

5. If they use the key to open the safe in the wall, the notebook is inside
   The notebook needs to be deciphered
   If the players don't figure out, the notebook is caesar deciphered, they might see it in a nightmare or get told by the demon (not explicitely though)

6. Outside there is a pile of rubbel with forms that seem to stem from a hole in the wall, but a piece is missing(see clue 1.)
   When they figured the puzzle out(tangram) the wall moves to reveal a door down to beneath the cabin
   Down there is the sacrifice chamber

7. In the sacrifice chamber there are runes on the wall
   if anyone can read the runes they reveal the story of the Nameless One
   when read the readers voice will change, as if speaking in tongues

8. In the sacrifice chamber there is an old tome
   the tome tells about how to summon and how to banish the demon
   the demon will want to stop them from finding out how to banish him

9. two bodies are in the sacrifice chamber
   one is a slit open person hung from the ceiling, the sacrifice
   the other one is the acolyte, in his hands a bloody improvised cross, made from a knife rammed trough a stick