Black Ichor of the Iron Obelisk

This is a one-shot dungeon/adventure I decided to cook up based on Dyson Logos’ commercial map offering, Black Ichor of the Iron Obelisk. It’s a small dungeon, which I kind of like, because that means a group of adventurers can probably make their way through in a single adventuring day. However, if you want to keep things going, I’ve included a passage to the Shadowfell version of the cavern that could lead your players to more (darker) adventures.

This adventure is for a group of 3-5 Dungeons & Dragons fifth edition 7-level player characters.

Adventure Background

Here’s what Mr Logos has to say about the Iron Obelisk:

The Iron Obelisk weeps in near silence – the pools of ichor growing around it, fed by its melancholy nature. The ichors seep down and flow where underground waters should, tainting the darkness with the ennui and melancholy of the pillar of iron. Slow grinding noises are heard nearby, as if the world is changing itself – pulling away as far is it can from the source of this ichor. The wound where the Iron Obelisk sits has grown forming a cave nearly 200 feet across where the world tries to isolate the rusted spike within it.

The Iron Obelisk has many powerful uses. Flakes of rust taken from the area around it and ground to dust make sleep spells incredibly more potent, whereas rust taken from the Obelisk itself can be used to counter most forms of mind control and charms. Bits of iron taken along with this rust can be worked into somber weapons and armour that spread their melancholic nature to their bearers, but also to their foes.

But those who touch the iron obelisk itself or the black ichor are cursed with the yearning sadness of the device. They will seek out places underground where the ichor can be found, and while the ichor does nothing to sate or alleviate the sadness, it calls to the cursed and bathing in it will indeed remove any other curses or diseases the target is afflicted with.

In fact, when adventuring underground, those cursed by the obelisk or the ichor will often find themselves in proximity with the ichor – even if it shouldn’t be there. There is a 25% chance that any adventure leading them underground will lead them to the black ichor in some way. It will replace water in dungeons and adventures, and will seem ominously ever-present until the curse is broken.

Reaching the Iron Obelisk

The iron obelisk and its cave are located in the ruins of an old swamp. In my own Forgotten Realms campaign, I see it as being a swamp within the Neverwinter Woods or possibly even in the Mere of Dead Men off the Sword Coast.

Who created the Iron Obelisk?

Over 1,000 years ago, the Dame of Darkness created the obelisk to draw her Material and Feywild selves back into her so she could become whole once more. However, the project was a failure as the obelisk was unable to pierce its way into the magic-potent Feywild.

Defeated, the Dame abandoned the Iron Obelisk, allowing it to continue to damage the very fabric of reality.

Enter the drow.

Nearly 600 years later, drow discovered the obelisk and built a lair around it to study and worship it. But eventually its melancholic powers were too great for even the dark elves. Servants of Lolth seized the caverns, and declared the locations cursed by the gods and shunned it. The only passage into the weeping cave was shut off, and it was never heard of again.

Until now.

Gith have discovered the Iron Obelisk.

Present day: a squad of githyanki, raiders a couple fiends, and a red dragon led by a half-dragon githyanki knight named Belcrom, believe that the black ichor and Iron Obelisk are tied to the illithid in some way. When the adventurers arrive, the Gith have already been in the caves for a couple days studying the ichor and the obelisk.

They wish to keep their motivations a secret, and will attack any who dare enter the caverns of the Iron Obelisk.

 

Locations in the Cave of the Obelisk

The map above shows the layout of the cave on the Material Plane side. Each square equals 10 feet. The following features are common throughout.

Ceilings

Unless otherwise noted, chamber ceilings are 15 feet high and corridor ceilings are 10 feet high.

Doors

Doors are made from worked stone on stone hinges. Doors are unlocked unless noted otherwise.

Illumination

Any room with the gith in it (not including Belcrom) has lanterns resting on any available surface. Belcrom, Ovodrin, Yubi, and Siles rely on their darkvision to see.

Black Ichor and the Iron Obelisk

Anyone who touches the iron obelisk itself or the black ichor are cursed with the yearning sadness of the device. They will seek out places underground where the ichor can be found, and while the ichor does nothing to sate or alleviate the sadness, it calls to the cursed and bathing in it will indeed remove any other curses or diseases the target is afflicted with.

In fact, when adventuring underground, those cursed by the obelisk or the ichor will often find themselves in proximity with the ichor – even if it shouldn’t be there. There is a 25% chance that any adventure leading them underground will lead them to the black ichor in some way. It will replace water in dungeons and adventures, and will seem ominously ever-present until the curse is broken.

 

1 – Guard Room

This was where the drow priest’s guards resided. The old guard room is empty save for five short swords hung along the wall that are still in good working order and five folded suits of studded leather armor that have dry rotted with age.

Scythe Trap

The old door to the armory and barracks is trapped unless the password “V’lshivan” is spoken.

• Noticing the trap requires a DC 15 Wisdom (Perception) track.
• Figuring out how the trap works and that it is a magical and mechanical trap requires a DC 15 Intelligence (Investigation) check.
• Finally, the trap can be disarmed with a DC 20 Dexterity (thieves tools) check or by fooling the password receiver with a DC 20 Intelligence (Arcana) check.
• If anyone attempts to open the door without first disarming the trap or speaking the password, they will take 2d10 slashing damage from a scythe blade that springs from the door frame.

 

2 – Workshop

The old workshop where the drow would create implements to perform their rituals on the black ichor on obelisk was in this nook. Now, three githanki warriors are rummaging through the old items looking for anything of value.

Attacked by the Gith

The githyanki do not wish others to know that they are in the Iron Obelisks’ caves. They’ve been instructed by Belcrom to attack anyone that enters that is not part of their party.

• One of the githyanki warriors will attempt to escape with his misty step and warn Belcrom in area 12.
• The remaining githyanki will fight until their hit points are reduced to 20, and then attempt to flee using their misty step.
• If the githyanki are defeated, they are carrying 1,100 gold worth of gems discovered throughout the lair.

Secret Door

A secret door is hidden behind an old old stone chair against the northern wall.

• It takes a DC 18 Wisdom (Perception) check to notice the secret door.
• Then, it takes a DC 15 Intelligence (Investigation) check to figure out how to activate it.

 

3 – Cistern

The old cistern for the drow is here. It, like all the other water in the caverns, has turned to the black ichor, too. A fresco of the priests adorn the walls. However, the black ichor has affected the frescos and now it seems like the paintings are crying.

• If someone touches the black ichor, they get the curse of the Iron Obelisk.

 

4 – Storage

This ancient room was where the drow once kept their supplies. It is all ruined by age and the presence of the black ichor.

 

5 – Kitchen

This old kitchen is covered floor-to-ceiling in dense cobwebs.

• A creature entering a webbed area for the first time on a turn or starting its turn there must succeed on a DC 12 Dexterity saving throw or become restrained by the webs.
• A restrained creature can use its action to try to escape, doing so with a successful DC 12 Strength (Athletics) or Dexterity (Acrobatics) check.
• Each 10-foot cube of giant webs has AC 10, 15 hit points, vulnerability to fire, and immunity to bludgeoning, piercing, and psychic damage.

 

6 – Banquet Hall

This room was the banquet hall. At the eastern end of the room is a statue of the Dame of Darkness covering her face.

• Whenever someone touches Betha’s hands, they are automatically transported to area 1 in the Shadowfell side of the Iron Obelisk.

 

7 – The Iron Obelisk

This large room is where the Iron Obelisk stands. Black ichor flows from it into the underground river that cuts through the caverns. Ovodrin, a young red dragon, realxes here, impatiently waiting for his half-brother, Belcrom would let them return to the astral plane.

The cavern is huge, with ceilings nearly 50 ft high, giving Ovodrin enough room to make his attacks from the air.

Ovodrin attacks!

• Ovodrin is bored and will attack simply because he has nothing better to do.
• However, Ovodrin is cocky, too. If he thinks there is trouble (such as the githyanki warriors from area 2 notifying Belcrom), he’ll brazenly try to fight off any intruders himself.
• If Ovodrin is reduced to 50 hp, he will flee to alert Belcrom in area 12.

 

8 – Sacrifice Pens

A lone githyanki warrior searches through the old slave pens for anything of value. Unfortunately, there isn’t much.

• If the githyanki warrior sees that he is outmatched or greatly outnumbered, he will misty step away and try to reach Ovodrin or Belcrom to warn them.

 

9 – High Priest’s Chambers

Time has been cruel to the High Priest of the Obelisk’s old chambers. Yellow mold grows over everything.

• If the mold is touched, it ejects a cloud of spores that fills a 10-foot cube originating from the mold.
• Any creature in the area must succeed on a DC 15 Constitution saving throw or take 11 (2d10) poison damage and become poisoned for 1 minute. While poisoned in this way, the creature takes 5 (1d10) poison damage at the start of each of its turns.
• The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a successful save.
• Sunlight or any amount of fire damage instantly destroys one patch of yellow mold.

 

10 – Meditation Platform

The drow priests sat for long hours weeping and meditating before the iron obelisk and its pools of dark ichor. Their old pillows remain, long ruined by the passage of a time.

The platform itself is 5 feet above the floor of the large chamber with the Iron Obelisk. Furthermore, the ceilings here are 30 feet high where it connects with area 7, and arc to 10 feet near the north wall.

A stone block where the high priest sat remains. Treasure was hidden inside, but it was already discovered by Belcrom, who avoided the trap. However, the trap is still active.

• Noticing that the stone block has been previously pushed requires a DC 12 Wisdom (Perception) check.
• The stone block is very heavy. It can be pushed aside with a successful DC 17 Strength check.
• The stone block, when pushed aside, triggers stone jaws from around its base.
• Noticing the trap takes a DC 20 Wisdom (Perception) check.
• Learning how to disarm the trap takes a DC 10 Intelligence (Investigation) check.
• Disarming the trap takes a DC 10 (thieves tool) check.
• When the trap is triggered, any creature pushing the stone block must make a DC 15 Dexterity saving throw or take 18 (4d10) and become restrained.
• The restrained creature or another creature can make a DC 20 Strength check to free the restrained target from the trap.

 

11 – Beast Room

A pet giant spider was once kept here. Now, two bored fiends, Yubi and Siles wander around, scheming to overthrow Belcrom and his gith.

• Yubi is a mezzoloth. He’s quick to action and will start any combat off by casting his darkness ability to give he and Siles advantage.
• Siles is a bearded devil. He fights quick and dirty, looking to take out clerics and paladins first.
• Both fiends are bound by their contracts to Belcrom and will fight to the death.

 

12 – Receiving Room

Before the drow would take their sacrifices into the baptism chamber to drown them, they would receive their victims in this room. As the captives begged for their lives, the drow would issue prayers and dress them in ceremonial garments.

Now, the room is in complete ruin.

Fighting Belcrom.

Belcrom meditates here, contemplating his group’s next move. He’s already disappointed that the obelisk is not connected to the illithid. Any intrusions he’ll see as annoyances to be dealt with quickly.

• Belcom is a half-dragon githyanki knight. Use the same stats as a githyanki knight with the following changes:
  • Belcrom has blindsight 10ft.
  • Belcrom speaks Draconic in addition to Gith.
  • He has a Fire Breath (Recharge 5-6). As an action, Belcrom exhales fire in a 15-foot cone. Each creature in that area must make a DC 15 Dexterity saving throw, taking 24 (7d6) fire damage on a failed save, or half as much on a successful one.
  • Belcrom has Damage Resistance against fire.
• Belcrom will try to keep plenty of distance between himself and the main group, using misty step to hit and run any big damage dealers such as rogues and spellcasters.
• If the party is close enough, he’ll try to hit as many as he can with his fire breath.
• If he drops to 40% of his hit points or lower, he’ll use Plane Shift to escape to the astral plane.

What’s next door?

• The door to area 13 is locked. Belcrom had opened it, but saw the Lonely inside and decided to leave it be. Unlocking the door requires a DC 15 Dexterity (thieves tools) check.
• Anyone near the door can hear the Lonely in area 12 weeping with a successful DC 13 Wisdom (Perception) check.

 

13 – Baptism Chamber

The ancient baptism chamber is where the drow priests of the Obelisk drowned their unwilling victims in the black ichor. The overpowering loneliness brought on by the black ichor has drawn one of the Sorrowsworn, a Lonely from the Shadowfell.

• The lonely is exasperated to see another creature and will immediately attack with its harpoon arms to attempt to catch its new “friends” with its sorrowful embrace attack.

 

Continued in the Shadowfell

That’s the Cavern of the Iron Obelisk and the Black Ichor. Next up, I’ll continue the adventure on its Shadowfell side where even weirder encounters await.

Thanks for reading!