The heart of the forest is tainted and needs to be cleansed. Use this dungeon as ancient ruins deep in the forest. The corruption disturbs the wildlife and people around it. It messes with the lives of all living things in the forest. The townspeaker of an elven tribe offers a hefty bounty to a group of valiant adventurers to take care of this. This adventure is intended for a group of four to six heroes of 5th level.
In the Material Plane, the world of fey and the creatures of the forest are considered to be a symbol of good. Fairies and sprites have kindred spirits. Druids and rangers form strong bonds with beasts and wild animals from this foreign land. However, the spectrum of good and evil is found everywhere. And the fey hold some of the darkest creatures. Monsters so vile and vicious that they match the power of some fiends and demons.
The elven tribe of Vel’Nyden struggles with one of these corrupted entities. The heart of the forest, as they call it, is the soul and life of the forest where they live. It is located hundreds of feet underground, deep inside ancient elven ruins. However, en evil fey spirit has tainted the heart. It is corrupted now and it prevents them from entering their millennia-old observatory. Besides, its growing influence summoned beasts and monstrosities in the ruins. The forest elves claim this observatory was built by their ancestors thousands of years ago. And though they live at the top of the trees in beautiful hand-crafted wooden houses, the elves love science and the study of the universe and the stars. They have used the observatory for generations and their understanding of the world surpasses any others’.
The elves haven’t been able to enter the observatory for weeks and it pains them. The situation worsens each day since the corruption of the heart of the forest reaches the elves’ souls and those of animals and beasts. Some of the tribe members have gone mad or fallen ill and lay unconscious in bed. Healers can’t find a cure for these afflictions. After a couple of elves died trying to defend the village from rabid wolves, Niahra understood they needed the help of outsiders.
Niahra is the Vel’Nyden’s leader. She is a tall and strong elf with brown hair and yellow eyes. She wears an armor fashioned from bear pelts. Her face seems to be coming out of the bear’s mouth on her cowl. She sends scouts to the outskirts of the forest and nearby human settlements to find a group of heroes who can help them. The elves do not have much gold to offer but their weapons and masterwork armors can be worn by great warriors or sold for a good price.
Niahra can guide the heroes to the entrance of the ruins, a 10-feet-diameter hole on the ground. The elves provide the heroes with plenty of ropes, spikes, and other handy climbing gear. However, Niahra explains to them the corruption becomes stronger the more the elves approach the heart of the forest; they cannot accompany the heroes inside. The elves stay and stand guard at the entrance from animals that have gone mad. Finally, the Niahra gives the adventurers an elven magic scroll. She explains they must find a way to place it on the surface of the heart of the forest. The scroll might heal and restore it to its former shape.
The Ancient Observatory
The following descriptions of areas 1 through 9 correspond to the underground observatory where the Tree of Death is located.
Terrain. The stone flooring of this place has seen better days. The heart of the forest’s roots have grown all over the place, piercing walls and floors. Humidity has caused considerable erosion damage as well.
Doors. All doors are unlocked unless stated otherwise.
Light. There aren’t any sources of light in this dungeon. The light of the day dies before reaching the end of the shaft that takes to area 1.
Smells and Sounds. The roots of the Tree of Death produce a smell of burnt charcoal. Now and then, the gears and wheels of the observatory’s mechanism make a chirring sound that echoes all over.
1. Main Hall
The adventurers must descend through the 10-feet-diameter hole for 100 feet. The elves’ climbing gear makes the task a lot easier. The heroes arrive in a large rectangular chamber. The north and south walls of this place sustain enormous humanoid statues with slim bodies. Their ears and subtle details make them look like elves, though they wear no clothes and have no faces.
The heart of the forest has grown vile, thorny roots that grew upward and reached this area; tree-like spikes sprouted from ruptured sections of the floor. Two gricks and one grell lurk in this area. They attack any living creature that descends from the hole.
A small tribe of troglodytes lives here. Scores of animal pelts lie in the center of the room; piles of bones are scattered all around. A large badly-made tent with bones and animal pelts is placed by the north wall. The troglodytes dug the tunnel to the main hall (area 1). This place is unknown to the elves, who have not come here since the place is corrupted. Black roots from the heart of the forest sprouted from the south wall and form a sort of bush.
If the heroes barge into this area, eight troglodytes threaten them with their clubs and large claws. If the heroes do not stand back and return from where they came, the troglodytes attack. Ten more non-combatant troglodytes flee to the north tunnel if a battle starts. That tunnel leads to a network of underground tunnels. These caverns are beyond the scope of this module and are left to the DM’s discretion.
3. Wall Fungi
The statue placed on the south wall depicts an elf wearing long robes and tunics. An underwater current nearby flows beneath this area. The humidity on the soil has caused small fungi to grow around the north and east walls of this room. The elves consider this as a good omen. A passive Wisdom (Nature) check score of 14 reveals the fungi aren’t edible. Any character that takes a bite of a mushroom must succeed on a DC 16 Constitution saving throw or become poisoned for one hour. If the character fails the save by 5 or more, they also acquire one level of exhaustion.
The center of the room holds a crystal ball on a stone pedestal. The elves consult the crystal ball to read the future behavior of the winds and the skies. They use it to scry those who enter their home and forest. Only a few of the elves can use the ball’s power. The crystal ball is attached to a stone dais though it can be removed with the right tools. Doing it by force breaks the ball.
Treasure. A character using thieves tools’ can remove the crystal ball from its dais with a successful DC 16 Dexterity check. The elves do not consider the crystal ball suitable payment. Though they might be persuaded to let it go as long as the heroes forgo the weapons and elven items that were supposed to be the agreed-upon payment.
Secret Door. A passive Perception score of 15 or higher reveals there is a small lever on the wall behind the statue. Pulling the lever reveals a secret passage to area 4.
4. Secret Armory
The elves store weapons and treasure here. They are, in general, a pacific people and their forest is rarely attacked. But the elves are well-prepared for these rare occasions. Some of the artifacts here are considered elven antiques and not even Niahra, their leader, feels comfortable using them.
Treasure. There are two masterwork longswords and two masterwork short swords. There is a cloak of elvenkind and two pairs of boots of elvenkind. An elven +1 longsword, and a +1 longbow are the rarest items. Niahra plans to give the magic weapons to the adventurers as payment for their help.
5. Light of Elvenkind
This room used to have four identical statues on each corner but the one on the southwest corner of the room was destroyed by the black roots of the corrupted heart not so long ago. A floating crystal the size of a fist hovers in the center of the room. The crystal projects a beam of purple light downward to yet another level 100 feet below (area 8). The light is a reflection of the heart of the forest’s health. Its usual green and yellow colors are gone. The corruption has turned the light violet with pink hues. This light is usually harmless. But now it burns those who come close to it.
The light goes down through a hole on the floor that descends 100 feet. This vertical shaft leads to area 8. Any creature that desires to go down the shaft must succeed on a DC 15 Dexterity saving throw the moment they start to climb down taking 20 (6d6) radiant damage on a failed save, or half as much damage on a successful one. The light ray is so hot and the space to go down so narrow that it is almost impossible to avoid getting burned.
The stone flooring in the corridor stops and becomes a beautiful,15-foot-long, sanded, ivory platform. The spherical chamber is in itself a mechanical wonder. From the center sphere, several ramifications of different lengths end in circular shapes. They all move or rotate in different directions, their colors represent the various Planes of Existence of our world. The elves use the observatory for scientific purposes and to answer questions about the universe. They do not have any interest in acquiring power or learning other people’s secrets.
The Vel’Nyden elves don’t know how this place came to be, in truth. They just believe their ancestors built it. They don’t understand the mechanics of how the observatory works either, they just know how to consult it. A character that makes a successful DC 17 Intelligence check learns how to use the observatory. A character who uses the observatory can cast the spell scrying and ask anything about a place or someone. Unlike the limitations stated in the spell’s description, using the observatory allows the caster to reach any plane of existence, instead of only the plane they are in.
7. Meditation Chamber
This chamber has a small wooden kiosk in the center. The elves use this place as a sweat lodge. They shut themselves inside the wooden structure and bathe themselves in vapor. A bonfire beneath the stone on the east wall heats it. It is a special kind of granite that turns hot easily. They then throw much water at it and the steam fills the whole place. One of the black roots of the heart of the forest pierced the floor of this room and grew through the heated stone.
This is a sacred place for the elves. It is a place for rituals and ceremonies to thank the heart of the forest for the blessings of life and nature. This is the closest most elves have ever been from the heart. Niahra is the only living elf who has gone down the last shaft. It descends a further 100 feet to the core of the forest, the heart. Several parts of the room are pierced and broken. The center of the room used to be a beautiful basin with clean water. The black roots of the heart destroyed it and created a horrible spikey bush.
Above the basin floats the counterpart of the crystal 100 feet above. The beam of purple light flows like a liquid in both directions. The crystal is suspended in mid-air and cannot be moved.
The corruption made a monster, a mix of thorns and roots. A roper was born. It attacks the heroes as soon as they descend.
9. heart of the forest
The heart of the forest looks like a giant acorn with leaves and vines around it. It glows with a green soft light and its roots’ bark is healthy and strong. The evil fey spirit corrupted and tainted the heart. A crimson eye that sees all those who come down grew on a side of the once healthy acorn. Its black corruption spread to all its roots and made them grow frenetically.
The heroes must come down the shaft and weaken the evil spirit so that they can place the elven magic scroll on it. The adventurers can stand on the roots of the heart and fight it from there. The corrupted heart attacks the minds of the heroes. Once the heart is weakened and reduce to 0 hit points, the elven scroll can do its magic and cleanse the core of the forest.
The heroes witness how the elven magic heals the core. The violet hot light becomes a soft green. The black roots reside and shorten. They become brown again and recover their healthy look. The atmosphere inside the ruins feels lighter and the heroes feel as if the whole forest sighed as if relieved.
Niahra and the elves in Vel’Nyden notice when the corruption is gone. The trees retake their former green and the animals of the forest find inner peace once more. When the heroes return, the elves have a traditional ceremony in their honor in the sweat lodge, near the healed heart of the forest. Niahra allows the heroes to keep the elven weaponry from the secret armory (area 4) in case they already found it. If not, she shows them the way to the room and gives them the items personally.