Rill's Mouth Mines

The abandoned Rill's Mouth Mines are located in the Dwendalian Empire a little over an hour and a half to the east of Alfield, and north of the Rillway Road. It served as the lair for a cult of Yeenoghu.

The lair's entrance is located among a series of large, rolling hills topped with broken shale and surrounded by tall weeds.

Layout
Mineshaft Yard

In a rocky, grassless valley between the hills, this yard contained large wooden tables, broken boxes, pickaxes, the remains of some rusted lanterns, and three empty carts.

Around the corner, hidden among the hills above the mine, is a locked and abandoned old shed.

Mine Entrance

Alongside the wooden supports of the mine shaft is a partial barricade on both sides of the entryway made up of piles of broken furniture, pickaxe handles, and broken wooden beams all stuck into each other. The gap through the barricade to enter the mine is roughly three feet wide, and the shaft continues on for 40 feet before widening into a larger area. Only a small amount of light extends from the entrance, and the rest of the shaft is in complete darkness.

Common Area

Forty feet into the mine, the shaft widens into a more open area with sloped ceilings. The space is around 35 feet across and widening even further to around 45–50 feet towards the back of the chamber, before descending into two different pathways.

Both shafts have wooden frames for support and curved in opposite directions downward at a steady 45-degree angle. Neither tunnel shows signs of change in air current or temperature. Both passageways seemed to contain equal amounts of footprints and traffic.

At the time of the cult's occupation, this chamber had a handful of tables, some chairs, sacks of mildewed rice grain, and dry-rotted burlap bags of supplies, strewn about. Additionally, there was an untapped ale and water barrel, a half-full hooded lantern that was partially rusted over, a crowbar, and a slightly rotted sledgehammer. On a small ladder lay a "Boom-Boom Stick"—dynamite.

Stretching across the opening of the shaft into the common area there was a rope connected to a large log affixed to the ceiling, set as a swinging trap against intruders.

Left Passage

The left passage descends and curves downward about 15–20 feet, rapidly curving to the left and then to the right for at least 25 feet. There were no traps in this passage.

Right Passage This passage curves down to the right. There was a slight depression on the right side of the 10-foot-wide shaft that turned out to be a three-and-a-half-foot-wide pit concealed by a piece of burlap sack. The passage continues down in a spiral-like curve for about 40 feet, then a tunnel continues 150 feet before it slowly levels out.

Ritual Altar Chamber

This chamber is long and has multiple levels. What once may have looked like a solid mining vein had become strewn with bones and flayed skin that was pinned to the rock walls with scavenged nails. Blood was spattered across them with intent, and a painted jagged smile of sharp teeth adorned four of these flayed hides. A faint source of light in the center platform of this chamber flickered from a small stone altar holding a cluster of candles. The altar had one of the marked, flayed skins stretched over it, as well as several glistening hearts, which were used in a ritual to Yeenoghu.

Y-Intersection The shaft beyond the altar chamber curves to the right in a wide spiral before it sharply turns to the right. It straightens out, and the shaft emerges into a chamber of mixed natural rock walls and simple stonework. This room acts as a second common room; two other shafts, heading to the left and right, marked this chamber as a Y-intersection.

Two thick, natural pillars of rock break the space open. They stand as load-bearing portions of the chamber, while a crumpled section of the floor drops into a pit below. This hole is around 50–60 feet deep, and it seems to have been an intentionally created well that has since seen disuse. Similar to the first common area, this chamber contained tables and stools strewn about the area, as well as crates, pickaxes, shovels, and a variety of tools.

Right Passage

This passage has collapsed and is no longer usable.

Left Passage

Along this branch, there were two closed doors. The passage continues deeper into the mine at a moderate grade for about 60 to 70 feet, before it levels off and turns upward for another 20 to 30 feet leading to stairs.

Prisoner Cells

The left passage contained latched doors to prison cells. Behind the doors there was a strong smell of decay emerging from four dead bodies that were in pieces and pushed to the back of the room.

Stair Passage Other than the large, 40-foot-deep pit in the upper portion of this tunnel where part of the floor has collapsed, this passage is marked by rough stairs that rise for about 6 feet.

These stairs lead to a short tunnel that sharply curves to the left toward a large 8- to 10-foot wide archway, where a set of double doors seemed to have once been but had long since been broken off their hinges. Beyond this broken doorway, the tunnel grows rougher and continues to snake for 100 feet through 10- to 15-foot wide tunnels, before opening up.

The deeper down this passage, the more a faint mixture of urine and citrus replaced the general smell of decaying earth and dust that permeated the remainder of the mine.

Last Chamber

Opening up to a large rocky alcove, this chamber is filled with stalactites, which hang from an uneven ceiling that ranges from 15 to 20 feet above the floor. A rough slope descends from the immediate entrance of this tunnel and hits a short wall before rising past it to a small platform at about 70 to 80 feet in, where this chamber and the mine end.

Marked by signs of abandonment, with broken digging equipment lying in the corners of this chamber and walls, this chamber appeared to have been the deepest portion the miners had dug before having given up hope when the veins became scarce. Gallery

History
In Sydenstar 835 PD, the mine served as the lair from which a group of gnolls coordinated an attack on Alfield. After the attack on Alfield the gnolls, cautious of being followed, hid their lair's entrance by deliberately sweeping and dusting their tracks around the mineshaft yard with dirt. They also camouflaged the location of the entrance with a 12×12-foot blanket of interwoven grasses.

The party that would become the Mighty Nein ventured into the mines to eliminate the gnolls.

When the Mighty Nein followed the gnolls to their lair they found, in the mineshaft yard, three carts that the gnolls had used to haul captives and spoils from Alfield. Three guard-hyenas were gathered around and licking the dried blood splatter on the carts.

In the Common Area Nott failed to notice a trap and sprung it, which caused a log to loudly slam against the rock wall of the shaft and thus alerted the gnolls deeper in the mine. After defeating two gnolls, Jester searched the room and found a "Boom-Boom Stick" and a sledgehammer.

Nott partially explored the left passage and found no traps, so the party chose to further explore the right passage with the expectation that the more important sections of the lair would be trapped.

When the party entered the Ritual Altar Chamber there were six gnolls gathered around the altar, along with a priest of their god Yeenoghu. As the gnolls were conducting a ceremony to Yeenoghu, the priest placed several hearts onto an altar and gave small, muffled barks and yipping sounds. After saying a prayer in broken common, the gnolls around them yipped in unison and then tore into and devoured the hearts. The priest thought that a manticore was a boon from Yeenoghu, and that by feeding and growing one, a manticore would provide strength to the pack and thus more meat and power in the future.

After the ritual to Yeenoghu, the priest left, along with two of the gnolls and the now visible pack leader. The party killed two gnolls before the creatures had a chance to act. When the remainder did react, two hyenas were immediately killed by Fjord's Armor of Agathys. Fjord and Molly carved through the third gnoll while Jester and Beau took out the fourth, and Molly and Fjord killed the last two hyenas as they were attempting to flee. Nott used Hideous Laughter to prevent the last gnoll from leaving the room before finishing it off with her short sword. There the party found a medicinal supplies chest containing:
 * 2 healer's kits
 * disinfectant herbs and fungi (enough for two uses)
 * When applied topically, the herbs and fungi could remove poisons if quickly applied to the wound that was poisoned.
 * a small, leather hand pack that contained 4 glass vials
 * 3 vials were shattered, and the last vial contained a greater healing potion.

After hearing a muffled explosion in the distance and what sounded like a low vocalization, cackling, and eventually the scream of a woman saying, 'No, my baby!', the party gave chase.

The party followed the mineshaft tunnel down towards the woman's voice they had heard. They eventually found a second large chamber containing two hyenas, a skeletal gnoll, and two regular gnolls bickering over a small human child. An explosion from nearby made the group pause before Nott, Fjord, Jester, and Molly initiated an ambush. Just as they were firing off their first attacks, a loud boom shook the interior of the chamber, causing dust and rocks to fall from the ceiling. A cloud of dust and smoke came billowing out of the right passage, followed shortly by a new figure entering the room: the cleric Shakäste, who had also come to help rescue villagers.

Together, they investigated the room. Alongside another "Boom-Boom Stick" and a number of bodies they found a woman, Herma, who turned out to be the mother of the young boy, Jules; and a half-elven man, Petrov. They brought the living and seven of the dead back to the surface, where Shakäste had a shelter with four more survivors.

Shakäste sent his familiar, a hummingbird called the Duchess, ahead to scout the tunnel beyond the second chamber. Learning that there were more gnolls, Nott and Fjord took point, sneaking ahead. He and Nott killed a gnoll quickly, but not before it signaled the rest of its pack.

Three more gnolls came to investigate, prompting another scuffle. They were shortly joined by their pack leader, which charged ahead to kick Beau into a well in the floor. Shakäste held the leader at bay so that Jester and Nott could take him down. Beau climbed out of the well. With the largest threat eliminated, the remaining gnolls went down quickly. Jester found 13 gold and three silver pieces with a two-handed glaive on the gnoll pack lord.

The next, and final, chamber of the mines contained two bound, human captives, some manner of humanoid priest wearing gnoll bones, a mother manticore, and her newborn cub. The manticore consumed a human captive before anything could be done.

Nott tried to sneak in and free the captives, but before Nott could finish untying the captives the manticore saw them entering the cavern, and combat was joined. A single strike from Nott's sword killed the cub and attracted the mother's full wrath.

Beau ran in to drag Nott out of the manticore's range, although a final parting bite knocked Nott unconscious. Meanwhile, the priest took Jester out, and Shakäste broke the priest's concentration on the spell paralyzing Fjord. This allowed Fjord to use a healing potion to revive Jester, who in turn revived Nott. Nott then used Hideous Laughter to momentarily incapacitate the manticore.

While the manticore was helpless with laughter, the party focused damage on the priest. Caleb struck the killing blow with a Fire Bolt, and the sight of the priest's burning head triggered a flood of memories that made him withdraw into himself. Shakäste landed two final blows on the badly hurt manticore, finally killing it with a bolt of radiant flame down its throat.

The Mighty Nein found the following loot in its nest:
 * A skeletal hand that had been mostly chewed through, though on a single fleshy finger it held a beautiful silver ring with a blue gem. Caleb later identified it as a Ring of Water Walking.
 * A refined and well-carved stick, which Caleb later identified as a Wand of Smiles.
 * Large chains attached to a set of unlocked manacles.