Rumblecusp

 is a volcanic island in the Swavain Islands, southwest of Nicodranas and northwest of Urukayxl in the Lucidian Ocean. It is scheduled to be the site of TravelerCon on the 26th of Unndilar, 836 PD.

Appearance
Dominated by the volcano that gives it its name, the island's shallow white sand beaches and rare trees create a tropical paradise. At a distance, it is dominated by a wild mountain range, with thin switchbacked ridges giving it the odd appearance of an opening flower. In its center rises a massive mountain with a lazy trail of smoke drifting from its peak. The majority of the island is dense, lush jungle, surrounded by a faint ring of white sand beaches against rocky cliffs. The jungle is so dense that it seems to rise and roil with the landscape, rising up over mountain ridges. Some of the trees push up and cause strange tower-like structures that grow much larger than all the others surrounding them. The volcano itself comes to a point, with no caldera visible. There is a bit of an orange glow from a faint magma trickle near the zenith of the mountain, and a fissure from which the smoke emerges.

From the southeastern inlet, a faint mist lies over a large portion of the outer jungle, giving the island an almost dream-like quality. Beneath the water are sandbanks that wind out beyond the beach, looking like white tendrils beneath the ocean. Rising above the mist, the trees are extremely tall, a hundred or more feet up with thick trunks. A little further in, on the path toward the base of the massive central volcano of Rumblecusp, is a clearing holding a small village.

Viridian, one of the leaders of the village, described the island as the central focus of the world, home to many strange slivers of different parts of the world that create the land mass. Beneath the trees are odd landmarks that shelter dangerous beasts that might be a surprise to find on the ocean, a number of unnatural dangerous denizens. To cross the island, moving carefully, she estimated would take a few days, and about eight hours to reach the base of the volcano from the village.

Vo Village
The village, known as Vo, consists of about two dozen or more structures built across the ground and into the tree canopies themselves. There are networks of ropes and other long pulleys and cords that are bound between trees at a distance, and there are buildings held aloft about fifty or sixty feet off the ground, with bridges connecting them. Elements of it appear to be built of driftwood, or carved from local trees, or from pieces of ships that have been scavenged. The villagers wear tattered clothing, leathers, skins, hide, rusted chain, and nothing else. There are no accessories; it is bare-bones basic attire. There is no decor bringing it beyond anything functional. There are heavy ropes tied to the higher trunks and branches, a massive tangle of treehouses built of makeshift scavenged materials, ship parts, local lumber, and intricately woven and grown vines and dried vegetation. A third of the buildings are built up above at different levels connected by bridges. Most of the structures are supported by thick, healthy green vines, braided, entwined, and tended to hold and wrap them as it the jungle itself had risen to support and help hold the village together, structure to structure. The buildings are diverse in styles, materials, and apparent age.

A central massive tree marks the middle point of the village, lush and perhaps 200-feet tall, with numerous levels of branches. In each of these branches, the vines have grown out to clutch another small homestead almost like a hand, and all of them have connected vine bridges. It resembles a high elven establishment mixed with nature, deliberate and balanced with the natural world around it.

The Winding Core
The location from which the villagers mine beautiful gems, diamonds, and "various gifts from the land that we can refine". The Winding Core is also an entrance to the Underdark.

The Shaded Tangle
The Shaded Tangle lies along the path towards the entrance to Vokodo’s lair within the mountain itself, a cold place where color seems to be muted, where the mists grow cold. There is no sound of any birds or insects, and the temperature drop and loss of color feels supernatural, as opposed to just a barren location. This is probably caused by an opening to the Shadowfell, causing the plane to bleed into the area and bringing new wildlife and creatures on the island.

The Ruin
The Ruin lies far to the north on the island. The natural environment around The Ruin is horribly malignant, with the trees in a deathly shade of sickness. Swarms of mosquitoes and groups of treats roam the location.

Fractured structures dot the surroundings of The Ruin. The pinnacle location is a seven-story spire that has been sharply cleft down the middle at an angle. The architecture of this region is reminiscent of that in the Ghostlands of Rosohna. These constructions seemed to have arrived alongside Vokodo's exit from the Astral Plane.

A large ghastly creature, as well as a group of spectral figures, occupy sarcophagi within the spire. The bodies were buried with ornamental armor, weaponry, and trinkets, and infernal script is detailed across the building and sarcophagi. The spectral creatures also spoke infernal.



Heaven Falls
Lying to the northeast, the Heaven Falls are still a mystery to the Vo people. It protects the ocean entrance to the interior of Vokodo’s lair. According to Viridian, it is a place where the water cascades not down, but up, falling toward the sky before curling into the mountain itself. Vokodo strictly forbids anyone go there. When the Nein reached Heaven Falls, they realized that the phenomenon is caused by water that is falling out of the Elemental Plane of Water from an opening at the bottom of the lagoon. The water is sent upwards for about 150 feet before breaking upon a cliff face, separating into small rapids, rivers and waterfalls that spill into multiple pools.

Behind the waterfall, there is a tunnel in the cliff face hidden by an illusion. The tunnel leads to a large cavern filled with boats. According to Viridian, when travelers decide to stay on the island, they are instructed to leave their vessels there. Beneath the water in this cave is another entrance to Vokodo's lair, similar to the one on the other side of the island.

Vokodo's Lair
Vokodo's underwater lair lies deep under the volcano, reachable by only a few hidden and guarded passageways. Viridian led the Mighty Nein through the one that she was aware of, which passed through an area of poisonous gas before reaching a pool filled with breathable water. Beneath the pool was a tunnel lined with dangerous torchblooms from the Elemental Plane of Fire that led downward to a gargantuan (at least a hundred feet across) underwater chamber of rough black glassy volcanic rock broken by heavy patches of torchblooms giving off pockets of light.Some of the rock walls themselves glowed faintly orange with heat from the proximity of the volcanic activity. The torchblooms lining the tunnel through which they entered closed it off once they were within the chamber. The lair itself is made of a network of tunnels that eventually lead to a central chamber, where Vokodo resides.

Whenever someone wanders too close to an entrance to the lair, there is a chance that they will become inexplicably drawn to the center chamber, and know the exact way to get there.

Society
Only a few dozen people inhabit the island. Pono estimated there were close to seventy when the Mighty Nein arrived there. However, Vilya stated later there were close to 120. There are several children in the village.

The people of the island worship Vokodo, and refer to him as a great fire god. The villagers refer to the great volcano of Rumblecusp as "Vokodo," stating that Vokodo both exists within, and is it. When newcomers get settled on the island, they must visit Vokodo at least once and give him a valuable gift to be accepted. The vilalgers must constantly give precious items to Vokodo to keep him satisfied, and in turn, they believe he will keep them safe and provide for them. Because of this, they do not own many material possessions outside of basic tools and furnishings. Their main activities seem to be mining and refining jewels and precious stone to give to Vokodo, and hunting and fishing for their food. They eat communal meals.

The Vo are led by three people who make important decisions together. The current leaders are Viridian, the spiritual leader; Terra, in charge of hunting; and Lukash, in charge of infrastructure. The spititual leader of the Vo travels to Vokodo's lair at regular intervals to bring him gifts in the name of the entire community.

Everyone in the village seems unable to recall who they were and where they came from before settling on Rumblecusp, although they do not seem to question it. After Greater Restoration was cast on Viridian, she regained her memories and revealed that something on the island made people forget who they were to ensure that they remain there and serve Vokodo.

History
The island has been populated for ten to eleven generations.

The Mighty Nein arrived on the island (fleeing from a dragon turtle) in preparation for TravelerCon upcoming in slightly over a week. They encountered several displacer beasts that were routed by two werebear inhabitants of the island, whom they befriended, and were led through the jungle to the village of the Vo people, followers of Vokodo.

The party are told by Viridian about various locations on the island and about Vokodo, and that they need to meet with Vokodo to gain his permission to hold TravelerCon. In the morning, she guides them along the path toward Vokodo's lair.



Flora

 * Strange flowers: When Yasha smelled a purple one, she felt compelled to eat it, but her strong constitution shrugged off the presumably negative effect it would have had on her. She was able to press an orange one into her book of flowers.
 * Carnivorous vines: Thin vines that dangle straight down, almost like curtains, that turn reddish at the tip. They are covered in tangled strips of decaying flesh holding an occasional bone.
 * Torchblooms: Native to the Elemental Plane of Fire.

Fauna

 * Displacer Beasts
 * Dinosaurs
 * Deinonychus
 * Tyrannosaurus rex
 * Bodaks
 * Creatures that live beneath the ground and exude a sticky substance into a pool above them to trap the unwary.
 * Will-o'-wisps
 * Draegloth

Trivia

 * Everywhere on the island, there is a creeping feeling of being watched. After flying away from the coast for 15 minutes in a straight line, Beau and Jester could still feel the gaze on them.
 * The memory loss seems to only begin to take effect when waking up after the second night on the island. On their second morning, Fjord, Jester, Caduceus and Yasha woke up with many missing memories of important events and loved ones.
 * Every morning when waking up from a long rest, the Mighty Nein have noticed that some of their items had completely vanished.
 * The island has several shards from multiple planes due to Vokodo crashing onto Rumblecusp.