Dungeon: The Bones

The mine beneath the Forge leads out into The Bones, the unfortunate name that residents of Neria have given the Underdark due to the many sites of ruins and evidence of the people who lived during the Time Before.
In order to successfully follow the trail of the missing students, the party has several tasks to accomplish.

• Speaking with the deep gnomes near the entrance to The Bones will grant the party relevant information about the students who passed through The Bones.
• Finding and helping the students being threatened by shattered souls will continue the story, as these students have just escaped from where they were being held and have plenty to say about the situation. The students can also provide somewhat accurate directions on how to find the Overseer and the other students.
  • If the party doesn't receive this information from the students, then they'll have to discover where the secret wall is on their own via Investigation or detect magic.
• A broken soul near the hidden area can be convinced to tell the party more about the angry souls in The Bones, and what happened to them.

Plot points/Scenes

It doesn't take long for the last signs of life to fade behind you; the light from the Forge is quickly swallowed by the darkness of The Bones, and the air grows cold, damp, and stale within minutes.
After following the tunnel from the Forge as far as you could, you find yourself in a large cavern. The ceiling of the cave rises several dozen feet above you, and while it makes you feel far less claustrophobic, it also makes you feel exposed. There's little to take cover behind, here, should something that calls The Bones home decide that you're trespassing - and there are several things that call The Bones home.
Fortunately, for the moment, it seems like the nearest sign of life might not be hostile, after all. You can see several roofs protruding from the cave walls, and, upon further investigation, you can make out doorways carved out of the stone beneath the patches of roofing. Warm light pools into the caverns from beyond the doorways, illuminating your path forward - for a time, at least.

The party's first decision when they enter The Bones proper is whether or not to investigate the deep gnome settlement not far from where the Forge empties out into The Bones. Should they decide to approach the svirfneblin, the party will find that they aren't told to leave, but they aren't immediately welcomed by anyone, either. A successful Investigation check (DC 15) will reveal the deep gnomes in their homes or stores, and that most of them seem just as interested in the party as the party does the settlement. If the party manages to Persuade (DC 15) the deep gnomes to trust the party, a handful of them will join the party in the large cavern that seems to serve as their main area of residence.

On the missing Forge students
"Aye, they came through about a week ago." An elderly gnome with white hair growing from everywhere but the top of his head points back towards the way you came. "They were heading north, deeper into The Bones. Our apothecary offered to send provisions with them, but the... What do they call him? Right, the Overseer. The Overseer assured us they wouldn't be going far."

On interaction with the Overseer
"Well, he didn't seem panicked." A woman with hair the color of brass wipes her hands on the apron she wears. "He seemed perfectly calm, in fact. I offered some provisions for their journey, but he assured me that they wouldn't be traveling long, and would be in one place again before the day was through."
"There's only so far you can get in that amount of time," says a man standing beside her, arm over her shoulders. "Mostly a few caverns that don't go anywhere. There used to be a tunnel that led deeper into The Bones, but the ground fell away and no one's bothered crossing the chasm yet. I suppose they could have gone east, but there's only so far in that direction you can go in the amount of time he seemed to imply."
"I just don't know where they could have done so safely." The woman frowns. "The Bones are full of tortured souls and memories of the past. Wherever they were going, I do hope they made it."
Reward: 25 XP

If the party is injured or needs a place to rest, the deep gnomes will offer their homes to the party. While this may not be relevant as they enter The Bones from the Forge, it may be the difference between life and death, if the party finds themselves having run afoul of an enemy they underestimated. The gnomes will not, however, offer to assist the party in their journey through The Bones, nor can they be persuaded to join them, no matter how much the party might try to persuade them.
Moving north, the party passes through a small tunnel and enters another large cavern. It's at this point that the party encounters a different type of enemy than what they've been fighting up to this point.

The three^[1] figures moving through the cavern in front of you do so oddly, and it takes a moment for your mind to register that the figures are floating an inch or two above the ground. Their forms are slightly translucent, and you can see the cave walls through the forms of the shadows hovering in the cavern. When one passes through a large boulder to appear on the other side of it, it becomes undeniably clear that the figures in the cavern aren't corporeal.

The party can attempt to sneak through the cavern and avoid the attention of these enemies, but because of the way the enemies are moving through the space, it is extremely difficult to manage (DC 25). If the check fails, then the enemies take notice of the party attempting to move through the cavern. These creatures are hostile by nature; they can't be talked down from combat, nor will they surrender at any point before their complete and total defeat.
As the party engages these creatures in combat, they find themselves in a position to study them in more detail. As the first of the beings falls, the party begins to see how these enemies are different than the others - their obvious lack of solid form notwithstanding.

The strange wisp of a figure lifts its head towards the ceiling, and it opens its mouth wide. It isn't a scream that comes from it, but a sigh. As its form begins to disappear from the material, several phantom pieces of metal fall towards the ground, as if finally breaking free from the body that they'd been trapped inside. Just before the creature disappears from your sight, you hear the quietest of whispers right beside your ear, almost as if it's inside of your head.
"...thank you..."

Rewards for this encounter ^[2]: 300 XP

Once the immediate danger of combat has passed, the party has a chance to reflect on what they just encountered. The party can roll Arcana (DC 15) to recognize the shapes and colors that the phantom metal took on as those similar to what is used by Rangers that construct chassis for their animal companions. If the Arcana check was passed, the party can then roll an Intelligence check (DC 15) in order to piece together that someone, it seems, was experimenting with creating chassis for people; the ruined souls left behind, angry and desperate for rest, are evidence that such experiments failed.
If the party explores the small tunnel leading north, they'll discover the chasm in the ground that the deep gnomes warned them about. They can attempt to cross the chasm (Acrobatics or Athletics, DC 20), but the tunnel only leads further into The Bones and seems unlikely to lead anywhere useful or relevant. Continuing east, the party will encounter three^[3] more shattered souls, drifting aimlessly around the ruins of a building from the Time Before. Some crumbling walls remain, a testament to what once stood here. The souls near the ruins will attack the party as soon as they come within 30 feet of them.
Rewards for this encounter^[4]: 300 XP
Moving east from the cavern where the four shattered souls were encountered, the party can then choose to move north or south. Moving south will lead them towards a tunnel that leads deeper into The Bones, currently occupied by three^[5] enemies: one shattered soul, and two failed experiments.
Rewards for this encounter^[6]: 200 XP
Moving north, either originally or after returning from the path south, the party will find themselves in a small cavern with not only enemies, but the first students from the Forge that the party has been able to find.

The cavern is split nearly in two by the stream that cuts through the middle of the space. Moss and mold has begun to grow along the banks of the stream, though the trees nearby are as dead as any of the others you've come across.

On the side of the stream closest to you are four^[7] failed experiments, pacing with an anxious energy in front of a group of frightened-looking people. The embroidered symbol on their robes and smocks marks them as students of the Forge, but it would seem as if this particular group of students is currently helpless, for one reason or another. All of them are empty-handed, and when they see you entering the cavern, they immediately begin pleading with you for help. The commotion causes the angry spirits to turn, and when they see that there's new prey closer to them, they move to attack.

Rewards for this encounter^[8]: 200 XP
Once the failed experiments threatening them are dealt with, the Forge students will gratefully tell you whatever they can. If Cororin is with the party, the students will have to be persuaded to speak freely (DC 12), but once they have assurance that nothing they say will fall poorly on them, they will share what they know with the party members.

On how they went missing
"It just... happened one day," one of the students offers. "We were in class, or practicing in the workshops, and there was suddenly an announcement that everyone was to meet the Overseer in the mines. The barrier was down - "
"Which it never is," supplies another student.
"Right," continues the first. "The barrier was down and the Overseer was talking about going through The Bones in order to avoid the aetherstorms if the shields went down again."
"It made sense at the time," a third student sighs. "We didn't even think to ask where we were going."

On where they were taken
"There's a... a secret wall or something." The student offering you the most information continues being helpful. Back through that cavern there, like you were trying to make your way back to the gnomes, except there's a tunnel that leads south. That opens up into a cavern and the wall is in there."
"It's a prison," interjects another student. "He took us to a prison."

On what happened in 'prison'
"He kept us in these... cages. He gated us off with lightning magic put us all to sleep when he'd come for one of us - which he did, a lot. One, two at a time at most."
"And then we'd hear the screams," supplies a younger student in a haunted voice that serves as evidence to her statement. "They were so loud. So awful."
"The smell was worse," offers another, prompting several other students to gag into their sleeves or hands. "Blood and piss and shit..."
"And then the smell of it all burning," concludes the quiet girl darkly.

Reward: 75 XP
The students will not, under any circumstances, accompany the party anywhere but to the deep gnome settlement. From there, the students will leave The Bones through the Forge, leaving the party to continue on their journey. The cavern that the students were talking about can be found by backtracking through the cavern immediately west of where the students were found. A second tunnel leading south opens up into a large cavern, full of ruins and spirits both.

You've never seen a place so deserving of the name 'The Bones' as this place. Remnants of old buildings litter the ground, like giant bones of the world itself. Scraps of metal are dangerously littering the ground, more common here than elsewhere in the caverns. They seem to be trailing towards a section of the cave on the east side of the space.

Floating between you and that section of cave are three^[9] darkened shadows, two of which you're unfortunately familiar with at this point. The third, however, nearly takes you by surprise with how human it looks. Like the others, it clearly lacks a solid form, but this figure is complete, if somewhat featureless. Several bands of incorporeal metal wind in and out of the form's 'body', resembling a nearly functional construct chassis. It turns towards you, and though you can't see its eyes, you can feel the weight of its gaze on you, and it feels too intelligent to ignore.

The two failed experiments in the cavern cannot be reasoned with, nor will they surrender. The broken soul in the cavern with them, however, is far more aware and coherent than the other beings in the room, and can be interacted with as a sentient being. It won't attack the party alongside the other spirits, but it will retaliate without hesitation if the party attacks it first. If the party pauses long enough to attempt to talk to the creature, they can get the soul to trust them enough to talk with a Persuasion roll (DC 15).

"We were... broken." Its voice is a whisper, a soft echo in the cavern around you. "He... broke us. Remade us. We are... the poor souls that... trusted him. We were the first... to follow him. Kept by him. We are... the first. We are... the failures."

If the party offers to put the spirit out of its misery, the spirit will happily agree. Regardless of how the party clears this encounter, they are now free to explore the cavern for the false wall the students mentioned.
Rewards for this encounter^[10]: 300 XP
Investigating the cave (DC 15) reveals that a nearby stream of water coming from the wall flows towards a wall just south of it. The water doesn't pool at the base of the cave wall, continuing its flow as if the wall weren't in the way at all. Players can attempt to walk through the wall, which is strange and disorienting, but possible. Players that pass a Wisdom save (DC 15) make it through the wall without getting turned around and backtracking back into the cavern they came from. Players can also attempt to dispel the magic that is keeping the insubstantial wall in place (DC 13).
On the other side of the wall, a small tunnel continue south, narrowing as it does. After several yards, the party encounters a small pool of light coming from what appears to be another area of The Bones made up entirely of caves. As they approach the light, the party can hear the faint hum of lightning in the air.

Stat blocks used in this scene

Failed Experiment

Medium Undead, Chaotic Evil

Armor Class 12

Hit Points 22

Speed: 30 ft

STR

13
( +1 )

DEX

15
( +2 )

CON

10
( +0 )

INT

7
( -2 )

WIS

19
( +4 )

CHA

6
( -2 )

Damage Immunities Poison

Condition Immunities Charmed, Exhaustion, Poisoned

Languages Common

Challenge Rating 1/4

Actions

Bite. Melee Weapon Attack: +2 to hit, reach 5 ft., one creature. Hit: 9 (2d6 + 2) piercing damage.
Claws. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 7 (2d4 + 2) slashing damage. If the target is a creature other than an elf or undead, it must succeed on a DC 10 Constitution saving throw or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Shattered Soul

Medium Undead, Chaotic Evil

Armor Class 12

Hit Points 22

Speed

STR

1
( -5 )

DEX

14
( +2 )

CON

11
( +0 )

INT

10
( +0 )

WIS

10
( +0 )

CHA

11
( +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

Challenge Rating 1/2

Incorporeal Movement. The specter 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.
Sunlight Sensitivity. While in sunlight, the specter has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Actions

Life Drain. Melee Spell Attack: +4 to hit, reach 5 ft., one creature. Hit: 10 (3d6) necrotic damage. The target must succeed on a DC 10 Constitution saving throw or its hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the creature finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.

Broken Soul

Medium Undead, Chaotic Evil

Armor Class 12

Hit Points 16

Speed: 40 ft

STR

6
( -2 )

DEX

14
( +2 )

CON

13
( +1 )

INT

6
( -2 )

WIS

10
( +0 )

CHA

8
( -1 )

Damage Vulnerabilities Radiant

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

Damage Immunities Necrotic, Poison

Condition Immunities Exhaustion, Frightened, Grappled, Paralyzed, Petrified, Poisoned, Prone, Restrained

Senses Darkvision 60 ft., Passive Perception 10

Challenge Rating 1

Amorphous. The shadow can move through a space as narrow as 1 inch wide without squeezing.
Shadow Stealth. While in dim light or darkness, the shadow can take the Hide action as a bonus action.
Sunlight Weakness. While in sunlight, the shadow has disadvantage on attack rolls, ability checks, and saving throws.

Actions

Strength Drain. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 9 (2d6 + 2) necrotic damage, and the target's Strength score is reduced by 1d4. The target dies if this reduces its Strength to 0. Otherwise, the reduction lasts until the target finishes a short or long rest.
If a non-evil humanoid dies from this attack, a new shadow rises from the corpse 1d4 hours later.

Balancing encounters for 5

[1] Two (2) shattered souls and two (2) failed experiments

[2] Rewards: 300 XP

[3] Three (3) shattered souls and two (2) failed experiments

[4] Rewards: 400 XP
[5] One (1) shattered soul and three (3) failed experiments
[6] Rewards: 250 XP

[7] Six (6) failed experiments
[8] Rewards: 300 XP
[9] One (1) broken soul, one (1) shattered soul, and one (1) failed experiment

[10] Rewards: 150 XP