One Shot adventfor 1st-4th level characters

The Whispering Sepulcher of Shadowdale

Deep beneath the rolling hills of Shadowdale, an ancient burial complex has begun to stir. The Whispering Sepulcher, sealed for centuries, pulses with unnatural life as its stone corridors echo with voices that should not exist. This horror-themed dungeon crawl for 1st-4th level characters explores a pre-Netherese tomb complex that has become corrupted by the Far Realm.

The adventure takes place in the Dalelands, specifically in the forested regions northwest of Shadowdale proper. This location is significant as it sits atop a confluence of ancient ley lines that once powered Netherese experiments in planar travel. When those experiments failed catastrophically, the resulting dimensional tears were hastily sealed within the burial complex of the mage-lord who conducted them.

Now, something has disturbed the seals. Reality bleeds at the edges as whispers from beyond seep through cracks in existence itself. The characters must navigate both physical dangers and threats to their very sanity as they descend into a tomb where the dead speak truths that living minds were never meant to comprehend.

Adventure Hooks

1. Elminster himself approaches the party, concerned about reports of villagers found wandering the woods near Shadowdale, speaking in languages that predate human civilization and drawing symbols that hurt to look upon.

2. A local shepherd's daughter has vanished after following "the pretty lights that sing" into a newly opened sinkhole. Her father offers his life savings and an heirloom amulet to anyone who will retrieve her.

3. The party awakens to find strange geometric patterns carved into their flesh while they slept at a Shadowdale inn. The wounds don't hurt, but they whisper constantly in voices not their own.

Opening Scene

The morning mist clings to your boots as you stand before a jagged wound in the earth. The sinkhole yawns twenty feet across, its edges lined with stones that seem to shimmer between purple and black in the weak dawn light. From somewhere far below comes a sound like wind through broken glass—or perhaps it's singing. The trees around the opening lean away as if repelled, their leaves withered despite the spring season. As you peer into the depths, you could swear the darkness peers back, and for just a moment, you hear your own voice whispering secrets you've never told anyone.

General Map Features

Environmental hazards include unstable stone floors, areas of altered gravity, and zones where reality grows thin
Multiple vertical levels connected by crumbling stairs, rope-accessible shafts, and areas requiring climbing
Doors sealed with pre-Netherese glyphs that respond to touch, sound, or specific emotions
Persistent whispers grow louder near areas of dimensional instability
Bioluminescent fungi provide dim light in some chambers, but their glow reveals things better left unseen
Temperature drops dramatically deeper in the complex, and breath becomes visible even in summer

Key Locations & Encounters

R1. The Throat of Whispers

Rough-hewn stone stairs spiral downward into darkness. The walls are covered in scratches—some ancient, others disturbingly fresh. As you descend, the whispers grow louder, speaking in languages both familiar and impossible.

1. Details: The spiral staircase descends 60 feet. Roots pierce through cracks, writhing slowly when touched.

2. Enemies/Creatures: 2x Stirge (MM p.284) mutated with translucent wings that show swirling galaxies within

3. Tactics/Behavior: The stirges attack anyone who speaks above a whisper, drawn to sound

4. Treasure: A silver holy symbol of Mystra (25 gp) clutched in a skeletal hand halfway down

5. Challenges & Checks: DC 12 Wisdom saving throw or gain one level of exhaustion from the disorienting whispers; DC 10 Athletics to navigate loose stones

6. Clues or Lore: Fresh scratches spell out "THE DOORS MUST STAY CLOSED" in Common

R2. Chamber of Reflected Sorrows

The chamber opens into a perfect sphere forty feet in diameter. Every surface is polished to mirror brightness, but the reflections show not yourselves—they show moments of loss and regret from your past, playing out in endless loops.

1. Details: No visible floor; characters must navigate using the curved walls. Gravity seems negotiable here.

2. Enemies/Creatures: 1x Specter (MM p.279) of the tomb's architect, driven mad by guilt

3. Tactics/Behavior: The specter emerges from mirrors, attempting to possess those who show remorse

4. Treasure: Crystallized Tear (wondrous item): When crushed, allows the user to cast Calm Emotions once

5. Challenges & Checks: DC 13 Wisdom save or be stunned for 1 round by visions; DC 12 Acrobatics to move along curved surfaces

6. Clues or Lore: The reflections sometimes show the architect placing something in the chamber's center before it vanished

R3. The Geometric Garden

Stone flowers with impossible angles grow from the floor, ceiling, and walls. Their petals open and close in patterns that make your eyes water. In the center, a fountain flows upward, its water hanging in the air like frozen rain.

1. Details: The "flowers" are actually fossilized Far Realm entities. Touching them causes brief visions of alien vistas.

2. Enemies/Creatures: 3x Twig Blight (MM p.32) made of crystallized flesh rather than wood

3. Tactics/Behavior: The blights remain motionless until someone disturbs the fountain, then swarm

4. Treasure: Vial of Suspended Water: Acts as a Potion of Healing but also grants ability to understand Deep Speech for 1 hour

5. Challenges & Checks: DC 14 Intelligence save or take 1d4 psychic damage from looking at the flowers too long; DC 15 Investigation to find hidden passage

6. Clues or Lore: The fountain's base contains equations that hint at the location of the seal chamber

R4. Hall of Hanging Whispers

Chains descend from the darkness above, each ending in a small silver bell. The bells ring without being touched, each producing not sound but spoken words—fragments of conversations, last words, unfinished confessions.

1. Details: The chamber is 30 feet wide and 80 feet long. Some chains hang low enough to block movement.

2. Enemies/Creatures: 2x Shadow (MM p.269) that hide within the chains

3. Tactics/Behavior: Shadows attempt to strength drain those who listen too closely to specific bells

4. Treasure: Bell of Silent Speech: When rung, allows telepathic communication with one creature for 10 minutes (3 charges)

5. Challenges & Checks: DC 11 Dexterity save to avoid chains when moving quickly; DC 13 Insight to discern meaningful whispers from babble

6. Clues or Lore: One bell repeats coordinates in Netherese, marking the true tomb location

R5. The Threshold Laboratory

Arcane equipment lies shattered across this vast chamber. In the center, a ring of standing stones surrounds a pool of liquid that reflects stars from no known sky. The air shimmers with barely contained energy.

1. Details: The pool is actually a dimensional weak point. Looking into it risks madness but may reveal truths.

2. Enemies/Creatures: 1x Gibbering Mouther (MM p.157) that was once the lead researcher

3. Tactics/Behavior: The mouther speaks with the researcher's voice between bouts of madness, pleading for death

4. Treasure: Lens of the Far Realm: Grants advantage on Investigation checks but user must make DC 10 Wisdom save or gain short-term madness

5. Challenges & Checks: DC 15 Arcana to safely interact with equipment; DC 13 Constitution save or gain one level of exhaustion from dimensional pressure

6. Clues or Lore: Research notes detail attempts to pierce the veil between realms and mention "the Sleeper Below"

R6. The Seal Chamber

The final chamber houses a massive stone seal covered in protective wards. Behind it, something immense shifts and whispers. Cracks spider across the seal's surface, leaking a luminous ichor that defies description.

1. Details: The seal is 20 feet in diameter. The room's geometry shifts subtly, making distance difficult to judge.

2. Enemies/Creatures: 1x Cult Fanatic (MM p.345) trying to break the seal, plus 2x Cultist (MM p.345)

3. Tactics/Behavior: The fanatic attempts to complete a ritual while cultists provide cover

4. Treasure: Amulet of Proof against Detection and Location, Spell Scroll of Protection from Evil and Good

5. Challenges & Checks: DC 16 Arcana or Religion to reinforce the seal; DC 14 Strength to push the massive stone components back into place

6. Clues or Lore: Ancient warnings indicate this seal is one of several holding back "the Hungering Void"

Important NPCs and Factions

Whisper - Ghostly Remnant

Race: Ghost (formerly human)
Alignment: Chaotic Neutral
Details: The spirit of a child who entered the tomb decades ago. Appears as a young girl whose form flickers between normal and grotesquely distorted. She knows the tomb's layout but speaks only in riddles and nursery rhymes. Helps the party if they show kindness but vanishes if threatened.

Malachar the Seeker - Cult Leader

Race: Human
Alignment: Chaotic Evil
Details: A former Zhentarim mage who discovered references to the tomb in forbidden texts. Believes breaking the seals will grant him power over reality itself. Utterly mad but brilliantly intelligent. May try to recruit or manipulate the party before revealing his true intentions.

The Shadowdale Watchers - Secretive Protectors

A clandestine group of rangers and druids who have guarded the tomb's location for generations
Will aid parties trying to reseal the tomb but may attack those who seek to plunder it
Led by Thornwick Greencloak, a halfling druid who speaks for the Old Oak of Shadowdale

The Whispering Chorus - Aberrant Collective

Not a faction but a psychic phenomenon—the collective consciousness of those who died in the original catastrophe
Attempts to communicate through dreams, visions, and possessed individuals
Seeks release through either the complete opening or permanent sealing of all dimensional rifts

The Whispering Sepulcher of Shadowdale