Rancid Waters (5e Quest)

For 4 characters of 1st level

Adventure Background

In the town of Briary, nestled at the forest's edge, desperation is beginning to set in. Over the past few days, its lifeblood - the freshwater from a spring deep within the Greenpine Forest - has turned to bile. Its foul-smelling and bitter to the taste, and coated in an oily film that sicken's those who consume it. Talk of witches, curses and monsters in the bog spread like wildfire.

Mayor Elaine Greaves, a weary but well-meaning women, offers coin, shelter and a place of honor at the Harvest Festival to anyone who can put an end to such a horror. Most locals are too frightened to accept the quest; even the few woodsmen who know the forest's trails won't go near the spring anymore.

And ancient horror stirs beneath the earth. A cult, hidden for decades, has returned in the caves near the spring - anything older than the forest, and long forgotten - has sown its spawn in the rancid waters, and one of them is nearly ready to hatch.

Overview

In this short one-shot adventure, the characters will venture in the caves hidden deep in the forest, face off against a cult of the toad-lizard god Laogzed and prevent the spreading of more of its spawns in the region by killing the Broodmother, a giant amphibian-reptile thing that is being fed and cared for by the cult.

Although this adventure starts in the small town of Briary, this can changed to fit your home setting.

Hook

Below are some hooks that can be used on your table:

The Water Tastes Wrong. The town mayor is offering gold to fix the problem with the water, before their scarce reserves of water and food run dry.

Missing Hunters. Two local trappers vanished near Greenpine. Their last trail led toward the cave-fed spring now tainting the town's water.

The Croaking Idol. A traveling priests warn of old swamp cults returning - he saw a toad-shaped idol buried in mud by the river and fled in fear.

THe Alchemist's Offer. A strange alchemist offers gold for parts of the fouling creatures. "hide, glands, eggs - anything not dissolved".

Briary

Population: ~650 inhabitants

Region: Southern frontier of a temperate kingdom, bordering the Greenpine Forest

Government: Small elected council; de facto led by Mayor Elaine Greaves

Common Races: Humans (majority), halflings, dwarves, and a few half-elves

Primary Industry: Hunting, herbalism, and small-scale agriculture

Defense: Local militia (15 part-time guards), plus 2 seasoned hunters who serve as scouts

Briary is a modest, isolated settlement built near the edge of the Greenpine Forest, a sprawling and ancient woodland. The town is a patchwork of moss-roofed cottages, smoke from hearthfires drifting over the treetops, and winding dirt paths that twist between hedgerows and low stone walls.

The town was founded nearly a century ago around a natural spring. This spring, fed by underground currents deep in the forest, has kept Briary alive—supplying water, attracting wildlife, and giving local alchemists and herbalists potent ingredients for their crafts.

Main Locations in Briary

The Old Spring Well

Located on the town's northern edge. Now sealed and guarded since the water turned foul.

The Fox and Firkin Tavern

A cozy, timber-framed building where news, rumors, and adventuring contracts are exchanged. Owned by Rilga, a no-nonsense dwarven matron who hears everything.

Greaves Manor

A large, ivy-clad home that houses Mayor Elaine Greaves and the town council. Acts as the de facto town hall and refuge during crises.

The Alchemist’s Shed

Run by a mysterious gnome known only as Vinter. A cluttered place of strange smells and stranger requests—offering coin for odd parts and oddities.

Shrine of the Wild Watcher

A small stone circle near the woods, dedicated to the local hunting deity. Tended by Brother Aldric, a reclusive cleric who’s recently warned of ancient evils returning.

Hunters Market

An open-air collection of stalls where pelts, meats, and forest herbs are traded weekly. Currently quiet, as most hunters and gatherers have gone missing or refuse to enter the forest.

Guardhouse

Contains the barracks for Briary’s small militia and stores emergency supplies. Captain Mera Voss, a former mercenary, trains the young militia members in her spare time.

Cultural Details

• Briary celebrates a Harvest Festival every fall, the biggest social event of the year. Heroes of the town are honored with seats at the central bonfire.

• Locals are deeply superstitious—fairy lights, bog curses, and forest gods are common topics.

• The town maintains a "Founders’ Log", a long record of births, deaths, and significant events—recently updated with ominous notes about the water crisis.

The Cave

Cavern Map by Tim Hartin

The areas, in terms of elevation, follow this order: The entrance of the cave descends into Area 1 -> Area 1 Ascends into Area 2, following a slope, but descends further into Area 3 - > Areas 3, 4 and 5 are on the same elevation.

1. Cave Entrance

A moss-choked hill slopes into a yawning black hole. The scent of mildew, rotting leaves, and something fouler wafts from below. The air is damp, and a faint croaking echoes intermittently, as though the cave itself were breathing.

Features

There are three natural columns made of stalactites and stalagmites fused together, that can be used as cover in case of the combat be brought to this area, or as hiding spot.

There are three paths: one at South, leading, to the Cult Sanctuary (area 2) and two at West, leading to the Fetid Chamber (area 3).

Paths: There are three entrances in this room, as mentioned below:

• Southern Entrance: Leads to Area 2. This entrance is trapped. (See Trapped Entrance below).

• Western Entrances: Both passages lead to Area 3. A foul smell can be sensed from the corridor that leads to the Area 3.

Investigating: If the characters decide to investigate the area:

• Investigation (DC 15): Discovers footprints—some booted, others webbed and inhuman.

• Survival (DC 15): Reveals the tracks are fresh; humanoid ones lead south, the webbed ones west.

Trapped Passage to Area 2

There's a tripwire connected with a bag filled with glands removed from the Foulings. Detecting the tripwire require a DC 15 Wisdom (Perception) check.

If the trap is triggered, the creature who crossed the tripwire, and all creatures in a 5-foot radius must succeed on a Constitution saving throw (DC 13) or suffer 2 poison damage. In addition, a fetid cloud that lasts for 1 round spreads through the area 1 and 2, alerting the cultists to the presence of intruders.

The trap can be disarmed with a DC 20 thieve's tools check, and avoiding the trap after noticing it requires a Dexterity saving throw against a DC of 15.

2. Sanctuary of Laogzed

The stale air is thick with incense and decay. At the far end stands a grotesque statue of a lizard-like being, with red glowing eyes, limbs warped and a strange blackish liquid drooling from its mouth.

Features

This area is dimly lit by the candles on top of the shrine. If the trap is triggered, the cultists are found in a gruesome scene: one of the trappers is being devoured alive.

If the cultists were alerted, the Trapper will be seen with his agonizing moans muffled by the mouth gag. The two troglodytes part of the cult will be camouflaged if the characters are detected.

Inhabitants

There are five inhabitants in this room: three cult members and two troglodytes. The cult members use the statistics of the Acolyte|Acolyte, but their spellcasting trait is the following: At Will: Primal Savagery, Poison Spray, Thaumaturgy; 1st-level (3 slots): Bane, Ray of Sickness, Healing Word.

Two of the cultists use face masks made of a strange hide-like material. The mask filter the poison, enabling them to stay close from the troglodytes. The other, the leader, wars a necklace of adaptation.

Developments

Once defeated, the players can rescue the trapper. His name is Gavid. One of his legs his partially devoured, and he's feverish, but alive...

Treasure

• On top of the Altar, there are two silver candle holders (15 gp each).
• Two of the cultists carry 2d4 gp.

• Two of the cultists use a gas mask, that turns the user immune to inhaled poison.

• The cult leader is wearing a talisman with the sacred symbol of Laogzed. This is a Necklace of Adaptation. He also carry a Potion of Water Breathing.

• The statue of laogzed has two cinnabar gemstones for eyes (15 gp each). Removing them seem to anger the god, as a faint roar can be heard echoing through the cave.

• The statue itself is a magical item. While the cinnabar gems are attached to the eye sockets, the statue drool's poison. It drools enough poison for 1d4 vials each day. The poison created by the statue loses potency after 8 hours. The statue can't be removed without extreme effort and, if removed, it loses all its magical properties.

4. Hatchery

This chamber is womb-like—humid, warm, and vile. Pale green eggs—hundreds—lie clumped in mucus-laced nests. Some shiver. Others are cracked and oozing a noxious ichor. From the shadows, faint croaks and chirps echo unnervingly.

Features

Investigating. Investigation (DC 15): Finds corpse of the other trapper.

Inhabitants

Three Lesser Foulings have already hatched from their eggs. Other eggs pulsate slowly. Each egg has 1 hit point and AC 5.

Treasure

The body of the trapper has a golden tooth (worth 9 gp), and a brass ring with the symbol of the local hunting deity (5 sp).

5. Broodmother's Lair

The stale air is thick with incense and decay. At the far end stands a grotesque statue of a lizard-like being, with red glowing eyes, limbs warped and a strange blackish liquid drooling from its mouth.

Features

A cavernous lake lies ahead, black and unmoving. Thick fungal growths pulse on the rocky walls. Something massive stirs beneath the surface, the water vibrating with every breath it takes. Above, glowing runes blink in sync with its heart.

Inhabitants

Beneath the waters, there's a Foulspawn Broothmother, a gigantic beast that looks something between a frog and a lizard.

Foulspawn Broodmother (CR 1/4). Large Aberration, AC 12, 20 HP, Str 15, Dex 12, Con 13. Bite +4, 2d4 +2 damage. Special Actions: Roll 1d6 at initiative, and at the start of the creature's turns. On 5-6, choose one:

• Breath Weapon: 15-ft. cone, 1d10 acid (DC 11 Dex save)
• Drag: Target grappled (DC 11 Str. save). Creature retreats up to its movement speed into the lake, dragging the victim (doesn't provoke opportunity attacks, 2d4 poison each turn finished in rancid water)

Developments

When the Foulspawn is defeated, the waters can finally be cleansed.

Treasure

If the foulspawn broodmother corpse or body parts are brought to the Alchemist, he thanks and pay the player characters, and fashion a Potion of Poison out of the creature's rancid blood.

Also, if the Trapper is saved, he will fashion some pieces of gear on downtime:

• Foulspawn Hide Armor: Hide Armor, doesn't impose Disadvantage on Stealth checks, grants 3 Damage Reduction against acid and contact poisons, and +2 on saving throws against contact poisons.

• Foulspawn Bone Shortbow: Regular shortbow, but add Strength modifier (up to a maximum of +2) to the damage of attacks made with it.

Conclusion

With the cult finally defeated and the foulspawn beasts slain, alongside with their eggs, the villagers can finally venture inside the cave and cleanse the waters. The villagers thank and pay them heroes for their deeds, and give them a position of honor in the upcoming Harvest Festival.

Rewards

• Treasure Promised by the Mayor: up to 150 gp
• If the Hunter is Retrieved Alive: He grants them a silver dagger (worth 51 gp if sold). He also offers to produce the following from the creatures: a composite shortbow and a special hide armor.
• Path in the Forest: up to four Hunting Traps can be retrieved and disarmed. (they can be sold all four for 10 gp total).
• Room 3: 2 sp can be found on the ground

Experience

Combat Awards

Name of Foe	XP per foe
Cultists and Troglodytes in Area 2	250 (adjusted 500 xp)
Foulspawn Hatchling in Area 4	75 xp
Broodmother Room 5	125 (adjusted 250 xp)

Non-Combat Awards

Task or Accomplishment	XP per Character
Disarming or avoiding Poison Trap in Corridor to Area 2	200 xp
if no party member is damaged by the cloud in Area 3	200 xp

The minimum total award for each character participating in this adventure is 112 experience points. (450 xp in total)

The maximum total award for each character participating in this adventure is 306 experience points. (1225 xp in total)

Downtime

Each character receives 7 downtime days at the conclusion of this adventure.

5.00

(one vote)

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