Developing a Twisted Plot Within an Adventure

One of my more recent adventures I completed for my patreon is called The Weeping Witch.  Below is the map I'm using.  A simple, but hopefully interesting, map. Three detailed areas.  It doesn't seem like a lot, but in this case the setup helps develop the plot.  Should a GM chose to ignore the setup, it is an adventure with some depth. 

Plot is usually a story element and sometimes used for adventures.  In this case, plot drives what has occurred and what will occur.  The players dictate the result. Let me use this adventure as an example.

The villagers of Scorn are irritated and exhausted.  The Harvest Moon is a few days away and each year at this time, the the Weeping Witch's cries are carried on the night's wind disturbing their sleep.  One of the precautions the villagers take is tying their children in their beds.  The cries of the Weeping Witch cause the children to sleepwalk into the forest where an abandon house sits.  

One of the children goes missing.  The villagers are suspicious.  The mother, Shara, is disliked and doesn't seem concern her son is missing.  Rumors of her practicing black magic have been whisper before, but now people are vocalizing their suspicions.  

When (if) the party investigates Shara's cabin they find, unlike all the other villagers, there are no bindings on her son's bed.  They also find bloodmoss, the villagers believe it is component of dark magics.  Shara denies everything and defies the party.

We've got the setup.  The obvious situation dangled before the party.  A witch that keeps everyone awake with her cries.  A boy has gone missing.  His mother took no precautions to protect the boy and possesses herbs that are considered to be evil.  

This is a distraction of reality, great fodder to pull your party along and give them a false sense of 'knowing' to act upon.  I like to develop these in an adventure to surprise the party, or it is a mystery to solve.  Both work out great.

The reality of it, the witch is the boy's mother.  The witch charmed Shara to watch over him.  Shara uses the bloodmoss to sedate him.  The boy is a werewolf.  If the boy is 'saved' and returned to the village he will kill many villagers.  nom nom nom

This situation lends itself to further adventures.  Allow events to unfold naturally and once a course is determined, the continuing consequences are the party's reward.  I do enjoy putting the party in the role of hero and then the result is their actions make the situation worse.  Much worse sometimes.

I use this device sparingly, it's not good to go all M. Night Shyamalan every adventure.  But sprinkling these types of situations into your game keep the players guessing.  Not to assume they 'know' what's going on until they get all the facts from every corner.