This adventure is designed for a party of five, 9th-level D&D 5th edition characters. It is intended to be completed within a single 4-hour session.

The Oracle of Wydale has disappeared! In her place there is only a note. The city council has chosen the party to investigate.

The note reads as follows.

“With this I’ll bring about all you fear For you’ll find no trace of the oracle. Unless you follow instructions clear She’ll suffer a fate most horrible. North past forest, farm, and city walls You must go to the great peak of despair. Then down behind Sullen falls To die in the mighty Urrisneth’s lair. – Urrisneth the Plaguebreath”

If the party investigates the Oracles room they will find it destroyed, as if a bull had run wild. A DC 19 Intelligence (nature) or Wisdom (medicine) check will notice a soft powdering of spores around the area, which belong to the sac fungus, a plant commonly used to fight infections.

A DC 21 Intelligence (history) check recognises that Urrisneth the Plaguebreath is the name of a green dragon from the north of Wydale that is known to kidnap but never eat his victims for an unknown reason. He was badly wounded 15 years ago by a group of troll hunters and hasn’t been heard from since.

What Happened? Last night the dragon Urrisneth broke into the Oracles chambers and kidnapped her. He did this for two reasons. 1. To stave off death he has become dependent on a medicine he created using sac fungus. However for it to work the fungus requires a constant supply of divine blood such as that found within the Oracle. 2. He left behind a note as a lure for strong adventurers. He views the them as good soil for growing his medicine and considers himself to powerful to be threatened by them.

The councillors recognise that ‘the great peak of despair’ could only be Serpent’s Lament, a pillar that is said to have held up the sky but is now a waterfall and source of the Sullen River. They offer the party 500gp each along with anything they find within, all untaxed, if they can return with the Oracle. If they can return with the Oracle but she is dead, they hold the same offer but will tax all they find 30% to pay for her resurrection.

Serpent’s Lament.

“Though your destination is a 5-day journey from Wydale it can be seen throughout the whole trip. A mighty column, seemingly carved from marble and left to weather the millennia stands reaching towards the sky. Most days its top disappears behind the clouds but on the rare instance it is clear you can glimpse its shattered top and the great blade that was plunged into it.

Beyond the final tree line the great Sullen Falls can be heard, transforming from a constant mist which rains down the pillar and into a dense waterfall. It is here, a mile down river, that your guides begin to set up camp. They promise to wait two days for you before returning to the capital.”

Magic Circle.

A 10-foot wide river winds up to a 15-foot radius pool that is fed by the waterfall. On all sides strangley shaped coniferous trees lean over to block out the sunlight.

Trap. A magical circle was placed in the woods around Sullen Falls by Urrisneth. This transforms all plant life within a 60ft radius around the waterfall into whipping tentacles that try to drag any living creatures within range underground. Any creatures not travelling through the river are attacked as if by the spell black tentacles (DC 14). Destroying the circle is a complex task and either requires a dispel magic (or similar effect) or a DC 16 Intelligence (arcana) check.

Perception Checks. DC 13 spots a glow coming from within the tree line. DC 21 can see that there is cavern behind the falls.

Treasure. The pool beneath the waterfall is 25 feet deep and at its bottom is a lead coffer held within the arms of an armoured skeleton. The coffer is trapped with a catapult spell and nails, anyone that opens it must make a DC 15 Dexterity save or take 24 (6d8) piercing damage, anyone that takes damage from these nails is exposed to rust strain. It contains 1700cp.

Rust Strain. Any humanoid or fey exposed to this disease must make a DC 15 Constituion saving throw on contract rust strain. Fey have disadvantage on this saving throw. Those with rust stain suffer disadvantage on all Strength checks except for attack rolls. At the end of each long rest an infected creature can make a new saving throw.

Waterfall Entrance.

A small cavern has been carved out and hidden behind the waterfall. There are two ways deeper into the pillar though one collapsed centuries ago. The skeletal arm of a crushed dwarf can still be seen sticking out from the rubble.

Traps. Shriekers (D&D 5e Monster Manual p138) have been planted around the entrance, alerting the tethered souls in this area and Urrisneth in his chamber with their shriek.

Creatures. A trio of dwarven tethered souls that were crushed by falling debris when serpent’s lament was originally destroyed. They are angry and seek to destroy anyone that comes near, but focus their hatred on fellow dwarves out of jealousy.

Curse. A curse was placed on the waterfall by Urrisneth. Anyone who consumes any water from the waterfall begins drowning where they stand (25% chance while travelling through it unless precautions are made). Each round a drowning creature can attempt a DC 16 Constitution saving throw to end the curse. For each failure they suffer one level of exhaustion.

False Hoard.

False Wall. Wood has been poorly painted to look like the caverns walls and placed in a short hall that branches from the main way. It has been placed as to be very easy to spot and requires only a DC 11 Wisdom (perception) check to notice. Behind the false wall is a small chamber seemingly filled with gold pieces.

Trap. As someone approaches the gold something seems to move from underneath. Moments later a great reptilian horror bursts out its eyes burning with a strange, pale green light. This is an illusory basilisk. It cannot harm or be harmed but has been programmed to stalk around the gold acting as if it will pounce at any moment. Meeting the eyes of the basilisk requires a DC 14 Constitution saving throw or seemingly become petrified. In reality they only becoming paralysed until damaged or healed. A DC 16 Wisdom saving throw sees through the illusion. 

Treasure. All the gold in this room is simply wooden disks glamoured to look like gold. There are 60,000 pieces in total (300lbs). Scattered amongst the disks is one tied with a feather and has the image of a blade emblazoned on it. If the disk is broken an invisible, moon-touched shortsword clatters to the ground 5 feet away. Due to the glow it emits the shortswords invisibility offers benefits to combat.

The Entrance Hall.
This main hall leads deeper into the pillar. Disgusting globs of flesh and bone have been formed into a large pile in the centre. Bones, hair, and other bits Urrisneth can’t digest or use for his plants are discarded in a pile here as a macabre scarecrow.

Creatures. A pair of kobolds are searching through the gore when the party arrives. When they notice the party a swarm of undigested attacks and consumes them before attacking the party.

Idols Rest.

The path widens into a circular chamber. At its centre is a dias on which a green idol shaped like a snake sits.

Creatures. The idol is actually a construct known as a serpent idol. It was placed here by Urrisneth and has been order to kill anyone that falls into the pit trap. 

Trap. The entire dias is actually an illusion over a 20-foot wide pit with a thin collumn at its center on which the serpent idol sits. Anyone that steps onto the dias must make a DC 17 Dexterity saving throw or fall into a 30-foot deep pit. At the bottom is a swarm of snakes which bite anyone within. Any creature that ends its turn inside the pit must make a DC 15 Constitution saving throw or take (7) 3d4 poison damage.

Urrisneth’s Chamber.

Marble walls have been sundered here revealing a small courtyard which would have once been the centre of an underground fortress. The courtyards floor has been overgrown with millions of red-stained mushrooms. On the far side of the courtyard a cylindrical metal cage hangs from the ceiling 10 feet off the ground. A dark-skinned woman in blood-stained white robes which you all recognise as the oracle sits slumped within. Most impressive of all though is the gigantic, green-scaled dragon sitting in the yards centre. Even from this distance you can see the various fungi growing across its body and sprouting from underneath its scales.

Creatures. Urrisneth (fungal dragon) has placed the oracle in a cage above his hoard of fungus. He is using her divine blood to feed his garden and plans to use the pcs as new fertiliser. He is arrogant, telling the heroes that he will happily accept their sacrifice to feed his garden. If the player try to strike a deal with him he will accept 500gp per person as sufficient payment for their lives. As it would inevitably lead to his death his is unwilling to give up the oracle. If combat breaks out he will attempt to knock out and capture creatures with divine blood first (any aasimar, divine soul sorcerer, or celstial pact warlock fits this description.)

Treasure. Beneath the rotten and overgrown bodies is 21gp, and a miniature chest which holds a ring of regeneration. This chect is actually the focus for a secret chest spell. A DC 14 Intelligence (arcana) check recognises this and allows the user to use an action to summon the chest from the astral plane which contains 75pp and a ruby of the war mage.

Tethered Soul

Medium Undead, Chaotic Evil

Armor Class 12s

Hit Points 22 (5d8)

Speed 0 ft., fly 30 ft. (hover)

STR 1 (-5) DEX 14 (+2) CON 11 (+0)

INT 10 (+0) WIS 10 (+0) CHA11 (+0)

Damage Resistances Acid, Cold, Fire, Lightning, Thunder; Bludgeoning, Piercing, and Slashing from Nonmagical Attacks

Damage Immunities Necrotic, Poison

Condition Immunities Charmed, Exhaustion, Grappled, Paralyzed, Petrified, Poisoned, Prone, Restrained, Unconscious

Senses Darkvision 60 ft., Passive Perception 10

Languages Understands all languages it knew in life but can’t speak

Challenge 2 (450 XP)

Proficiency Bonus +2

Incorporeal Movement. The Tethered Soul can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

Ectoplasmic Form. If the tethered soul’s tether is destroyed it becomes ectoplasm, losing all of its resistances, flying, and incorporeal movement. Its speed becomes 15 feet.

Sunlight Sensitivity. While in sunlight, the Tethered Soul has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Tether. The tethered soul is connected to its original body by an ectoplasmic tether that’s 40 feet long. It cannot travel past this distance from its body unless the tether is destroyed. The tether has 5 AC and 6 HP.

Actions

Forceful Slam. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 10 (3d6) force damage.

Undigested Swarm

Medium swarm of Tiny undead, chaotic evil

Armour Class 15 (natural armour)

Hit Points 36 (8d8)

Speed 30 ft.

STR 12 (+1) DEX 11 (+0) CON 11 (+0)

INT 5 (-3) WIS 12 (+1) CHA 5 (-3)   

Damage Resistances bludgeoning, piercing, slashing

Condition Immunities charmed, frightened, paralyzed, prone, stunned

Senses passive Perception 11

Languages –

Challenge 2 (450 XP)

Special Traits

Devour. As a bonus action, the swarm can grapple a prone creature whose space it occupies.

Sticky Tsunami. Whenever the swarm moves into a creature’s space or starts its turn in another creature’s space, that other creature must make a successful DC 13 Dexterity saving throw or fall prone. A prone creature must make a successful DC 13 Dexterity (acrobatics) check to stand up in a space occupied by the swarm.

Swarm. The swarm can occupy another creature’s space and vice versa, and the swarm can move through any opening one inch wide.

Actions

Digest. Melee Weapon Attack: +3 to hit, reach 0 ft., one target in the swarm’s space. Hit: 10 (4d4) acid damage, or 5 (2d4) acid damage if the swarm has half its hit points or fewer.

Serpent Idol

Tiny Construct, Neutral Evil

Armor Class 9

Hit Points 93 (11d8 + 44)

Speed 10 ft.

STR 6 (-2) DEX 9 (-1) CON 18 (+4)

INT 6 (-2) WIS 10 (+0) CHA 5 (-3)

Damage Immunities Cold, Lightning, Poison

Resistance Bludgeoning, Piercing, and Slashing from Nonmagical Attacks

Condition Immunities Charmed, Exhaustion, Frightened, Paralyzed, Petrified, Poisoned

Senses Darkvision 60 ft., Passive Perception 10

Languages Understands the languages of its creator but can’t speak

Challenge 5 (1,800 XP)

Proficiency Bonus +3

Immutable Form. The serpent idol is immune to any spell or effect that would alter its form.

Magic Resistance. The serpent idol has advantage on saving throws against spells and other magical effects.

Tainted Air. All creatures within 30 feet of the serpent idol take a 1d4 penalty to all saving throws against poison.

Actions

Calcifying Breath (Recharge 5-6) The idol releases a petrifying poison in a 15 foot cone. Affected creatures must make a DC 13 Constitution saving throw, on a failed save its Dexterity score is reduced by 1d4. The target petrifies if this reduces its Dexterity to 0. Otherwise, the reduction lasts until the target finishes a short or long rest.

Dragon, Fungus, Adult

Family: Dragon – Fungus

Huge dragon, chaotic evil

Armour Class 19 (natural armour)

Hit Points 229 (17d12 + 119)

Speed 40 ft., fly 80 ft. (hover)

STR 24 (+7) DEX 10 (+0) CON 25 (+7)

INT 16 (+3) WIS 13 (+1) CHA 21 (+5)

Saving Throws Dex +5, Con +12, Wis +6, Cha +10

Skills Arcana +13, History +13, Perception +11, Persuasion +10, Stealth +5

Damage Immunities cold

Condition Immunities charmed, frightened

Senses blindsight 60 ft. darkvision 120 ft. passive Perception 21

Languages Common, Draconic, Sylvan

Challenge 14 (11,500 XP)

Special Traits

Creeping Rot. Poison damage dealt by the fungus dragon ignores resistance to poison damage, but not poison immunity.

Legendary Resistance (3/Day). If the dragon fails a saving throw, it can choose to succeed instead.

Actions

Multiattack. The dragon can use its Withering Aura. It then makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 18 (2d10 + 7) piercing damage plus 7 (2d6) poison damage.

Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 14 (2d6 + 7) slashing damage plus 3 (1d6) poison damage.

Tail. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 16 (2d8 + 7) bludgeoning damage.

Withering Aura. All creatures of the dragon’s choice that are within 120 feet must succeed a DC 18 Wisdom saving throw or become frightened for 1 minute. A creature repeats the saving throw at the end of each of its turns, ending the effort on itself on a success. If a creature fails the saving throw by 5 or more its body becomes host to the dragon’s spores. It is permanently poisoned. If the saving throw is successful or the effect ends for it, the creature is immune to the dragon’s Withering Aura for the next 24 hours.

Rotten Breath. (Recharge 5-6). The dragon exhales plague carrying vapours in a 60- foot cone. Each creature in that area must make a DC 20 Dexterity saving throw, taking 31 (9d6) poison damage and 31 (9d6) necrotic damage on a failed save, or half as much damage on a successful one.

Puff. The dragon magically teleports to any open space within 100 feet. All creatures within 10 feet of it must make a DC 18 Constitution saving throw, taking 22 (5d8) poison damage on a failed save.

Reaction

Hallucination. When the dragon is targeted by a ranged attack it can create an illusory double increasing its AC by 4 against that attack. 

Legendary Actions

The dragon can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. The dragon regains spent legendary actions at the start of its turn.

Detect. The dragon makes a Wisdom (Perception) check.

Tail Attack. The dragon makes a tail attack.

Regrowth (Costs 2 Actions). The fungus which makes up the dragon’s body begins to reform by sucking the life out of those around it. All creatures within 5 feet of the dragon takes 1d6 necrotic damage. The dragon regains hit points equal to half the damage dealt.