Players enter a happy village, where everyone turns out to be mind-controlled by brain-slugs. The heroes will need to figure out what’s going on, find the path towards the center of the slug’s hive-mind, and destroy it (or make peace with it).
A vast sentient underground lake - the hivemind of mind-controlling slugs. Wants to bring about an “Apotheosis” (a global utopia) by taking control of all the minds. Speaks in creepy high-pitched sing-song voice. “We are Harmony. We bring joy and peace to all living beings.”
Entering the Clearwater Village
When traveling between locations, the players visit a lovely peaceful village.
You’re walking down a narrow road towards the Clearwater village. You’ve heard that people there need some help with a few chores, and figured that it sounds like a quiet and peaceful place to rest between the adventures while making a bit of money.
They meet a goofy old man welcoming them to the village.
As you walk closer to the houses, you see an old man waving at you, he’s wearing a charming hat.
Old Man McGuucket: Hey fellas! What brings you to Clearwater? Everyone calls me Old Man McGucket, how can I help cha?
As they walk into the village, they see that everybody is extremely nice and welcoming.
One unusual thing you notice is that all people here really love colorful hats - top-hats, cowboy hats, fedoras, etc.
The players see the tavern, a *small church, an old windmill.
Players will one person, without a hat, running away, but the guards quickly apprehend him, claiming he’s a murderer.
You see some sort of commotion from the window. You see a man running away from two guards “Hey, get him!”. By the time you’re outside, you see them carrying him, unconscious, back in the direction of the prison.
Later they see him wearing a hat.
The people in the tavern will get more and more insistent in inviting the players to check out their basement, where they have a ""great selection of foods and wines"".
Discovering the Slugs
If players capture a person and remove the hat, they see a green slug underneath it. If they remove the slug, the person falls on the floor and starts crying, thanking them for his freedom. It is revealed that everyone in the village is controlled by psychic brain-slugs, attached to their heads, wearing hats as a disguise (ratatouille-style). Players can also be ambushed by a group of villagers trying to assimilate them.
Gradually it becomes clear that things aren’t so black and white - the slug hive-mind (calling itself Harmony) is trying to “bring peace and joy to all the living creatures”, to build a utopia. Turning murderers and alcoholics into productive members of society, curing the depression of a suicidal person(by controlling their thoughts), etc.
At the windmill they will see the Friendly Frank - local farmer who has been pretending to be mind-controlled (by wearing a hat), gathering salt, preparing to fight off the invasion.
At the church players will meet Father Lucius. He will give them a moralizing speech, tell them about the upcoming apotheosis, and, depending on how the players react, is likely to ring a church bell summoning the villagers to assmilate the players.
The Old Well
Players can find it by following one of the villagers (the brain slugs have to leave their hosts once every few days to feed), or by liberating one of the mind-controlled villagers and asking them.
Underneath the Well
Players descend into the well, find a bunch of tunnels, mind-controlled giant spiders and centepedes, and a vast underground lake glowing with eerie emerald green color - Harmony, the coalescion of brain-slugs, the main hive-mind.
Harmony will tell players that it is thousands of years old, for most of it’s existence the slugs could only posess the local creatures (giant spiders, rats, centipedes). It can’t think or see on it’s own, it can only use the intelligence and senses of the hosts. After the well has ran out of water, the villagers have descended to investigate, it was able to posess one of them, and that was the first time it had access to human-level intelligence. It will say comes in peace and wants to bring about a utopia.
The lake can be destroyed by pouring the bags of salt the Friendly Frank has been collecting at his windmill (In case of a fight, Harmony can tell the spiders/rats/centipedes to attack). They can also try to persuade Harmony to leave (like in The World’s End), or try to find some path to symbiosis.
Depending on what happens at the lake, Harmony can become the player’s ally, or the villagers will thank and reward them for their liberation (except for the villagers who liked the symbiosis).