Adventure Title
Night/Midnight/Shadow/Darkness of (the) Tribe/People/Folk

Alternate title
Demon/Devil/Fiend/Horror of the Tower

Opening Scene
A mountain range that is Obscure where they encounter Militia that is/are Unfriendly

Plot hook and draw
An anonymous letter that is/has Attempted blackmail or extortion

Plot Concept
Complete an infernal ritual that is motivated by The voices have spoken...

Primary Antagonist
A nefarious cult who/that is Unpredictable

Plot fulfillment and location
A sorcerers tome from A trap-filled dungeon