Deadliest Dungeon Designs - Harbinger's Hideout - Encounter for Six 3rd Level Characters

Harbinger's Hideout Header

A Hard Encounter for six 3rd level Characters

Dwarven Forge Sets Required

DDD Area 1


Howdy everybody, Doom the Imp here, back with more devious dungeon antics.

Imagine a being, far and distant from where we reside, who craved the opportunity to walk among the boring nothingness you humans call “land” and claim it for their own. How they would use their own influence over one of their disciples to gain access to the world they so deliciously wanted to alter.

Then stay a while, and SHUT UP! While I tell you how to tell this story to other people.


A week ago a prisoner escaped from the local constable. That same day, three bounty hunters were dispatched after the fugitive. But after two days, they have not returned. The PCs will get paid if they can return the prisoner alive, and bring any news as to what happened to the hunters. 


The prisoner is a Warlock named Korren, sworn to Cyäegha (said See-eh-gg-hah), a questionable patron of destructive and nihilistic nature, with tentacles to spare. Before being apprehended by the town guard, he was having bizarre dreams and violent episodes in public. He was seen lurching around, convulsing, speaking in a bizarre language, and randomly shooting off detrimental magical effects. Unknown to Korren, he had been chosen as the vessel for his patron to enter this world. This terrible, otherworldly force is now trying to set off a chain of events which will allow it to enter the Prime Material.

The local watch apprehended Korren, sending out word to the Mages’ Conclave (or another Arcane based organization in your game) to help determine what the ramblings were about. Before the Conclave could reach the town, he had another outburst and disintegrated the wall of his cell. After escaping into the woods, he followed a vision from his patron and uncovered a hidden cave complex a day’s travel away from the town.

Once within, however, he discovered it wasn’t a refuge so much as a new prison as he was greeted by the glowing eyes and drooling mouths of two ravenous beasts. These Roper Mongrels had been infused with other-worldly powers by Cyäegha and never sleep, guarding the entrance of the cave but also keeping Korren within. Once inside the cave, he was ordered to obtain the materials necessary to start conducting the ritual. He resisted the directives, and growing impatient Cyäegha wrestled the minor control necessary to start their ascent.

Meanwhile, a trio of bounty hunters was dispatched to bring the warlock back to town before there was any more trouble. The bounty hunters tracked him to his cavernous refuge, and blazed their path for an easy return. The arrival of the three hunters proved to be the most fortuitous of happenings as the rituals could be completed sooner with their fresh bodies.

After completing the ritual, Korren came back in control, his hands stained with blood and viscera. Cyäegha echoes in his head, dubbing him the Harbinger, and to expect them shortly. He now apprehensively awaits the impending manifestation of Cyäegha, lost to its whims.


The Constable

Wants the Warlock back before they’re able to hurt themselves or anyone else. Also needs them back as the Mages’ Conclave he’s called isn’t an organization he’d like to get on the bad side of; they don’t take kindly to people wasting their time.

The Harbinger - Korren

Was unaware until he reached the cave what Cyäegha’s intent was. Has since re-evaluated his acceptance of the gifts received and participation with his tentacled Patron. He doesn’t want to be handed over to the Arcane organization however, as he assumes they will not be gentle in extracting information from him. He’s very willing to help PC’s reverse the rituals, but at the first sign of escape, will attempt to flee, as he doesn’t know when the Patron will take full control of his body again.

The Patron - Cyäegha (See Appendix A)

Wants a foothold onto the material plane and is willing to go to any lengths to achieve this. The ravings of the Warlock have described it as a gigantic black mass of tentacles, with a single green eye at the center. Manipulative, and would promise whatever to whomever if it helped their goals, but has no intentions of following through. It is a nihilistic and vengeful Ancient, and has been disturbed from its long slumber. As such, it must punish the world for deigning to exist at the same time as itself. It is able to read Intelligent creatures’ minds, to better see their innermost desires.

The Roper Mongrels (See Appendix B)

Dire wolves whose bodies have been infused with eldritch power by Cyäegha. No longer normal wolves, they have been bewitched by the Patron to be the dangerous creatures they are. They have large tendrils and spikes growing from their haunch, and a tongue that stretches 30' out to lash opponents and grapple them. Their main directive from the Patron is to protect the Warlock and keep him in the caverns, preferably on the crystal platform.

DDD The Adventure


The Cave Entrance

The cave lies a day’s foot travel to the northeast of town. The bounty hunters left blazes to mark their trail, so they could easily find their way back with the fugitive. The PCs can find and follow these blazes. The trail eventually leads to a cliff wall, with abundant underbrush covering it all.

Read or paraphrase the following aloud to the players:

“The forest you have been trekking through clears into a glade and a cliff wall comes into full view. A healthy growth of vines and underbrush cover the wall and the surrounding clearing. Torchlight left staked in the ground light up the area, and the air is heavy with the tinge of copper.”

DC 14 Intelligence (Investigation) or Wisdom (Survival) ability check: A trail of bloody drag marks streak the ground leading towards a particularly heavily obscured portion of the wall. The thick underbrush hides a cave entrance. The cave entrance is a 10’ wide passage that leads 30’ in until it’s blocked by a crude wooden gate - this is where Area A begins. If the PCs didn’t discover the bloody drag marks outside, they will notice them in this passage. The bloody trail continues down the entire passage beyond the gate.

Read or paraphrase the following aloud to the players:

“After unveiling the hidden entrance within the cliff wall, the air becomes heavy with the wet signature of mold and decay. A tunnel lies before you, ending with the sight of a crude wooden gate, seemingly made in a hurry to block entry...or is it to keep something in?”

The crude wooden gate is unlocked, but a DC 14 Intelligence (Investigation) check reveals it is rigged with a bell that will ring when the gate is opened. Once the bell is rung, the Mongrels in Area C are alerted, and will wait in the shadows until a creature steps onto the floor of Area A. The string to the bell can be cut from the outside, allowing for a stealthy entry. This requires a DC 14 Dexterity (Sleight of Hand or Thieves’ Tools) check to disable it without setting it off. 

Area A

Area A

A small cave entrance awaits on the other side of the crude gate. The floor of this cave is about 10’ below the height of the tunnel, and much of the ground is difficult to traverse. If the bell on the gate has been triggered, then two Roper Mongrels from Area C will attack here.

If the bell has been triggered, read or paraphrase the following aloud to the players:

“The stench of mildew grows as you push through the gate. Through the torchlight, the wet and uneven ground below you shimmers. A passage to the left lies in shadows, while a soft glow and a quiet, inhuman mumbling grabs your attention from the passage to the right. But before you can get your grounding, a low growl emanates from the left as you are met with the glowing green eyes of two massive spined dog-like creatures, their teeth bared and physique stretched into a horrific state.”

If the bell has been disarmed, instead read or paraphrase the following aloud to the players:

“The stench of mildew grows as you push through the gate. Through the torchlight, the wet and uneven ground below you shimmers. A passage to the left lies in shadows, while a soft glow and a quiet, inhuman mumbling grabs your attention from the passage to the right.”

If the bell wasn’t disarmed, the Mongrels attack whoever is closest with their Tongue ability to start out, trying to drag their victims over to Area C, and under the influence of the fungus. For the full stat block of the Roper Mongrels, see Appendix B.

If the bell was disarmed, the Mongrels rest in Area C until the PC’s interact with the Warlock in Area B. At that point, they will stealthily maneuver over to Area B and attack whoever is closest with their Tongue ability to attempt to split the party. The beasts will also come investigate any loud noises or disturbances.

A section of the floor of Area A is marked as rough terrain. In addition to the normal movement penalty, any creature who falls prone on these spaces suffers 3 (1d4) points of slashing damage from the sharp stalagmites and jagged rocks covering the ground.

Area B

Area B

This large chamber holds the Harbinger. It has a sizeable platform of interlocking crystals that are the source of the soft light that pushes through the tunnels. On top of this platform stands the Harbinger, currently under possession of the Patron. The manacles he wears are covered in gently pulsating runes, seemingly actively enchanted. 

Read or paraphrase the following aloud to the players:

“The cavern walls dance with the soft light emerging from the crystal platform in the center of the room. Standing in the center of this platform is a figure; tattered and dirty, with crimson stains over his clothes and manacled hands. His eyes closed, he sways slightly, his posture is eerily straight as he mutters a strange chant. The language is other-worldly comprised of sounds that grate on your ears and should not be emanating from a human form. To your right, there is a small passage which is boarded up, while ahead of you a passage splits in two directions.”

The boarded up wall leads to Area B2.

He will not interact with the PC’s until they either approach the platform or they attempt to speak or directly interact with him. The glowing crystal platform he’s standing on is a magic stasis field, holding him in place. Any attempt to remove the Harbinger/Patron from the platform while the manacles are on instantly fails as the field keeps him tethered to the platform. 

After they approach or speak to the Harbinger, read or paraphrase the following aloud to the players:

“The figure’s eyes snap open and focus on your group. They fill with an unearthly green glow and gaze upon you with indifferent calculation. After sizing you up, he speaks in an eerie rasping voice not his own that pierces the air of the cave:

‘Stench of life...erupts my senses...calls to eradicate...allow your screams...the last breath...of pitiful you stay...soon will witness...moist darkness everywhere!’

The Warlock reaches out with its chained hands, curling them upwards. A rumbling can be heard around you, and a cacophonous THUD as stone falls on stone. A slew of stones have crushed the wooden gate, and blocked the entrance of the cave.”

TERRAIN NOTE: Remove the Crude Wooden Gate at the entrance and replace it with the Solid Insert Wall to represent the cave-in blocking the entrance.

The Harbinger then crumples to the floor; it was too much exertion on his body, and Cyäegha has temporarily lost control. 

NOTE: If the party was able to sneak past the Mongrels, they will now attempt to sneak over and attempt a surprise attack. 

After a moment, the Harbinger comes to his senses and struggles to his feet. His demeanor is very different from when he was the vessel for Cyäegha. Sweat covers his brow, and he struggles to breathe.

Read or paraphrase the following aloud to the players:

“His eyes find all of you, scared and wild, his breath short and quick. Sweat covers his brow and he seems sickly and worn. Hoarsely he speaks out:

‘What...what happened? Oh it wasn’t a dream. Please, you must help me escape. Help me out of these chains. We must reverse the bindings!’”

The manacles that hold the Harbinger are magically enclosed by runes, and cannot be unlocked or broken by any means, until the bindings are broken. The stasis field will not prevent others from stepping on and off of the platform, and any attempt to dispel magic on the manacles or the platform itself fails while all three of the bindings remain unbroken. 

The Harbinger has fragmented memories of what has happened, but is sure that the Patron’s ascension is imminent. He tells of the three bindings that will allow Cyäegha to fully realize themselves in the Material Plane, and while not entirely sure how to reverse the effects, he remembers fighting them on carrying them out. There should still be instructions on how to carry out the tasks close to the bindings, if that may help them reverse the effects. From this moment, the PC’s have 5 minutes to reverse the bindings, at which point the Patron breaks through to the Prime Material Plane within the Harbinger’s form.

Each minute roll a d10 following the success/failure chart listed here. On a successful roll, the Harbinger keeps their sanity and control over their actions for the next minute. On a failure, the Patron takes over their actions for the next minute.

Minute Success Failure
1 01-09 10
2 01-07 08-10
3 01-05 06-10
4 01-03 04-10
5 01 02-10

While the Harbinger is in control, he will attempt to help them as much as he can from his chained position.

When Cyäegha wrestles control, will do whatever they can to impede the group’s progress. Choose one of the actions below to hinder the PC’s:

  • Floor Quake - Creates rough terrain. The ability affects a 10' radius chosen by the Patron. The range of the affected area can be anywhere within line of sight of the Patron/Warlock. The first time a creature moves through the affected squares on their turn, or ends their turn on an affected square, must succeed on a DC 13 Dexterity saving throw or take 2d4 slashing damage.
  • Tentacle Swarm - Clay tendrils erupt from the ground, restraining targets. The tentacles have a range of 30' from the Patron, and are considered a Ranged Spell Attack from the Patron, and as such uses the bonus to hit (+6) for its attack bonus. If the hit succeeds, the target takes no damage but is instead grappled. The subject may attempt to escape the grapple on its turn by spending an action to make a DC 15 Strength (Athletics) or Dexterity (Acrobatics) ability check. On a successful roll, the subject will land on an unoccupied square next to the tentacle.
  • Vacuum - Sends out a “magnetic” pulse that draws creatures back into the clutches of the Patron. The Patron may select up to 3 creatures to affect with this ability per minute. Those creatures must succeed on a DC 14 Constitution saving throw, or be pulled against their will from wherever they are 20' closer to the crystal circle the Patron is standing on.

After two seals have been reversed, or after the time limit has been reached, the Harbinger screams out, hunched over in pain:

“It’’s taking over!! I can’t...I can’t hold it anymore!”

He begins to float, and his eyes roll back as the dark powers of Cyäegha take over. No matter how much time they have remaining, the Patron takes full control of the Harbinger, and breaks out of their bindings. For help running this encounter, look to Appendix A

The PC’s are still allowed to remove the third binding, and at such time, the Patron loses the ability attached to that seal (as indicated in Appendix A). The platform and the manacles also both lose their magic once the final binding is removed, and the soft glow from the platform ends. If the PC’s are able to remove the manacles and take the Harbinger off of the platform, Cyäegha loses its final tether, and Korren is free from its control once more. 

In keeping a notation of the time it takes the PC’s to perform these unbinding rituals and attempting to track it “out of combat”, consider making the deliberation of what to do to be part of the in game time it takes to interact with these rituals. This way, you can maintain a sense of urgency for the players.

Area B2

Area B2

This room houses the chained crystal shard used as a ritual binding and the dead body of one of the bounty hunters.

Read or paraphrase the following aloud to the players:

“A hastily boarded up wall sits within this opening, a slowly pulsating magenta hue shines through the cracks.”

The wall is of shoddy build and material, so it is only a DC 11 Strength ability check to break through or a DC 10 Intelligence check to pry it apart.

Once removed, the PC’s see this:

Read or paraphrase the following aloud to the players:

“The pulsating magenta tint centers from a chained crystal affixed on the wall. The lifeless body of an adventurer lays beside it, eyes open and mouth agape.”

A DC 12 Intelligence (Investigation or Medicine) check reveals that there are no wounds on the body, and that its gear indicates it to be one of the hunters sent out to find the Warlock.

Etched into the wall sits a phrase in Common:

“To tether the master,
A soul is required,
Placed in pure crystal,
A life for a life“

The crystal houses the soul of the hunter, and must be released to unbind the seal. A creature must make 3 consecutive successful checks to release the soul within the shard. This can be achieved one of two ways:

A successful DC 14 Intelligence (Arcana) check dispels the magic within the crystal and the soul escapes.


A successful DC 14 Intelligence (Religion) check coaxes the soul to break through the magic itself, and helps it pass on.

A failure results in 4 (1d6) points of necrotic damage to the creature, as the crystal attempts to rip their soul out. Three failures result in the soul of the creature attempting to unbind the soul being trapped in the crystal as well. Any creature achieving three successes will release all souls trapped in the crystal.

If any physical attack is made towards the crystal, a repellant force keeps it from connecting, until the soul is released from it, and the attacker suffers 4 (1d6) points of necrotic damage.

If the Horn of Blasting from Area E is used on the crystal, it shatters the crystal and releases the soul instantly.

Area C

Area C

This room is where the Roper Mongrels begin, and is where you find one of the seals in the fungal growths all around it.

Read or paraphrase the following aloud to the players:

“Shadows encompass the passage, the smell of mildew stinging the nostrils. Spattering the uneven floor are small clumps of mutli-colored fungus. With each step forward, the fungus covers the walls and the floors, emanating from a mound at the end of the passage. A carving in Common on the floor reads:

“Cover the land to please the master,
Must spread the spores all the faster
Grow the crops or face disaster”

A DC 14 Wisdom (Nature) or Intelligence (Investigation) reveals that the fungus does not grow on any of the small mineral veins within the room. This purplish mineral matches in texture and color the mineral vein in the passage between Area D and E.

After discovering the mineral, a character (DM’s choice) understands that sprinkling this crushed mineral over the fungus will burn it away. Sprinkling it in this way takes an Action to perform, and removes spores in a 10' radius per action.

If a creature attempts to remove the fungus or burn it away with fire, it releases its spores out in a 15' radius. Any creatures subjected to this spray must make a DC 14 Constitution saving throw. On a failure, the creature is charmed into protecting the clusters in the surrounding area. The creature will attack anything the clusters deem a threat, and will not leave the immediate area. The creature may make additional Constitution saving throws at the end of their turn to resist the effects.

Any fungus attempted to be removed without the mineral grows back after 2 rounds. When the fungus has finally been removed, the PC’s find that the mound in the end of the passage was actually the body of one of the hunters.

Area D

Area D

Read or paraphrase the following aloud to the players:

“At the end of this passage sits a summoning circle, drawn in blood, encapsulating the area. A body lays at the foot of the circle, bloodied and with an open wound in its chest. A bloodstained empty bowl sits at its center, a beating heart sitting on a plate beside it.”

Carved in the floor next to the circle in Common:

“A heart, a heart, a beating heart! 
Fill it with life, demands the master”

The PC’s must forcefully squeeze the blood out of the heart into the bowl (or at least out of the heart). This requires a DC 12 Strength ability check to push the blood out, and to completely empty the heart requires 3 consecutive checks.

After each Strength ability check, anyone within earshot must make a DC 14 Wisdom saving throw as the heart wheezes out a gurgling screech. On a failure, creatures take 4 (1d6) points of sonic damage and are now frightened and cannot come near the heart for the next minute.

Area E

Area E

Read or paraphrase the following aloud to the players:

“A dead end cavern wall, a faint breeze blows through its cracks.”

A DC 15 Wisdom (Perception) check reveals a suspicious hand-sized hole within the wall.

Placing a hand inside finds two ropes within it, one on the left and right.

Right - Pulling this rope causes the wall to slide out and reveal the secrets behind it.

Left - Pulling this rope causes a boulder to fall from the ceiling. The creature who is pulling the rope must make a DC 13 Dexterity saving throw to dodge the boulder, or suffer 9 (2d8) points of bludgeoning damage.

Within the hidden room are a few objects stockpiled by the Warlock: 

  • A bag of 15 gems, each priced at 150 gp
  • Curved horn - Horn of Blasting - it only has two charges and no chance of backfire (for more information about the Horn, go to Appendix C)

If the Horn of Blasting is used on the caved-in wall, the PC’s are able to break through the boulder in one blast (regardless of damage done). It is also extremely effective against the crystal in Area B2.

Appendix A:

The Patron Encounter:

Cyäegha is still coming into power, and must rely on the strength of the Warlock’s abilities to warp the plane they are on. The Patron wants to walk free, and as soon as they are rid of these pests they will be, so it will use its harshest abilities to get rid of the PC’s. 


HP: 49 (7d8 + 14) AC: 14
STR: 11 (+0) Speed: 30'
DEX: 14 (+2) Skills: Arcana: +5, Persuasion: +7 
CON: 14 (+2) Senses: Darkvision: 60'
INT: 16 (+3) Languages: Common, Deep Speech
WIS: 12 (+1) Challenge: 5
CHA: 17 (+3) Damage Resistances: Bludgeoning, Piercing, and Slashing from Nonmagical Attacks that aren't Silvered
Innate Spellcasting.
The Patron’s innate spellcasting ability is Charisma. It can innately cast the following spells, requiring no material components:

At will: levitate (self only), mage armor (self only)
Spellcasting. The Patron is a 7th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 14, +6 to hit with spell attacks). It knows the following warlock spells:

Cantrips (at will): eldritch blast, mage hand, minor illusion, shocking grasp

1st–4th level (4 4th-level slots): banishment, burning hands, crown of madness, hellish rebuke, magic circle, scorching ray, stinking cloud, suggestion, wall of fire
Newly Awakened.
When the Patron makes an ability check or saving throw, it can use its reaction to add a d6 to the roll. It can do this after the roll is made but before any of the roll’s effects occur.
Melee Weapon Attack: +3 to hit, reach 5', one target. Hit: 3 (1d6) slashing damage.
The Patron can take 2 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 Patron regains spent legendary actions at the start of its turn.
  • Cast a Spell (Costs 2 Actions). The patron casts a spell from its list of prepared spells, using a spell slot as normal.
  • Fungal Gas (Costs 1 Action). The Patron releases a spore cloud out in a 15' radius. Any creature subjected to this spray must make a DC 14 Constitution saving throw. On a failure, the creature is influenced into protecting the Patron. The affected creature will attack anything the Patron deems a threat, and will not leave its side. The affected creature may make additional Constitution Saving Throws at the end of their turn to resist the effects. On a success, the creature is unaffected by the spores for the next 24 hours.
  • Soak (Costs 1 Action). Once per combat, the Patron is able to draw forth the life force of those around them. Each creature within a 30' radius of the creature must make a DC 14 Constitution saving throw. On a failure, the affected creature loses a number of hit points equal to 1d6+3, as the necrotic energy drains them. The Patron then regains a number of hit points equal to half of the total number of hit points lost.

For every seal that the PCs have unbound, the Harbinger loses an associated ability, as listed below:.

  • Seal 1 ability (Soul Crystal): Allows the use of the “cast a spell” ability
  • Seal 2 ability (Fungal Growth): Allows the “fungal gas” ability
  • Seal 3 ability (Heart): Gives Max HP and allows the “soak” ability

Consider the opportunity that the PC’s may have the chance to dispel the Patron from the Warlock’s body if they cannot unlock the runic manacles, or remove the Harbinger/Patron from the platform. Things like Intelligence (Arcana/Religion) checks to banish it once it has been weakened, a dispel magic spell where the DC is 10 + the Patron’s Cha modifier + 1 for each unbroken binding, or perhaps even a dispel evil and good (if strong enough). Use this idea if you would appreciate a more roleplay heavy solution to this encounter.

Appendix B:

Roper Mongrel statistics:

HP: 37 (5d10+10) AC: 14
STR: 17 (+3) Speed: 40'
DEX: 15 (+2) Skills: Perception +3, Stealth +4
CON: 15 (+2) Senses: Passive Perception 13
INT: 8 (-1) Languages: -
WIS: 12 (+1) Challenge: 2
CHA: 7 (-2) Damage Resistances: -
Keen Hearing and Smell. The mongrel has advantage on Wisdom (Perception) checks that rely on hearing and smell.

Pack Tactics. The mongrel has advantage on an attack roll against a creature if at least one of the mongrel’s allies is within 5' of the creature and the ally isn’t incapacitated.
Bite. Melee Weapon Attack: +5 to hit, reach 5', one target. Hit: 10 (2d6+3) piercing damage. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be knocked prone.

Lashing Tendril. Melee Weapon Attack: +5 to hit, reach 25', one target. Hit: 6 (1d6 + 3) piercing damage. If the target is a creature, it must succeed on a DC 14 Dexterity/Strength saving throw or be thrown prone and grappled by the tongue. As a bonus action, the Roper Mongrel may retract its tendril and pull the grappled target in 10'. 
Once per round at the end of another creature’s turn, the Roper Mongrel may strike out with its Lashing Tendril attack. They can only do this if they are not currently engaged in a grapple with an opponent.

Appendix C:


Horn of Blasting

You can use an action to speak the horn's command word and then blow the horn, which emits a thunderous blast in a 30-foot cone that is audible 600 feet away. Each creature in the cone must make a DC 15 Constitution saving throw. On a failed save, a creature takes 5d6 thunder damage and is deafened for 1 minute. On a successful save, a creature takes half as much damage and isn't deafened. Creatures and objects made of glass or crystal have disadvantage on the saving throw and take 10d6 thunder damage instead of 5d6.