L2-28. Shrine of Beltar — Maw of the Deep Mistress

The Pillar-Way to the Maw (read-aloud)

Shrine of Beltar (read-aloud)

What happened here (355 CY)

“The Trespass of Measure”

• High Theurge Vhalcaryn Rel-Daen (Wee Jas) ran ruby conduits from the ley-node (back toward the north-west caverns) to this shrine, seeking to domesticate Deep Earth beneath measure.
• Beltar answered with Stone-Spite: a retaliatory surge that blew the shrine, shook the south approach (collapsed chambers), and spider-cracked the lower level.
• Vhalcaryn’s pattern was ripped into the node—he survives as the Shadow-Wight bound beneath the obelisk.

(Arcana/Religion DC 13 in corridor or chamber: read the ruby inlay’s west-to-node direction; DC 15 adds the theological “law capped the pit; the pit bit back”.)

The East Corridor (to the shrine)

• Length & look: 60–80 ft, Pillars every 10 ft; murals of pits, teeth, and falling tithes; ruby floor chevrons point east.
• Hazards:
• Tilted flagstones: Moving faster than half speed → DEX save DC 12 or slide 5 ft (no damage; loud scrape advances the shrine’s clock by 1—see below).
• Ruby scree drifts: Stealth checks at −1 unless feet are wrapped/soft-soled.

Overhead Drop from L1-20

“Judgment Chute”

Placement: At the east end of the pillar-way, directly beneath the L1-20. Suel Temple antechamber. A concealed down–shaft (2½-ft × 6-ft mouth) opens and drops victims to the shrine floor, 10 ft from the Maw-Well.

Trap Specs (DM Quick)

Trigger (above): Pressure bar hidden in the L1-20 threshold; Perception DC 14 to notice hairline seams; Investigation DC 13 to find the rocking stone; Thieves’ Tools DC 14 to wedge or pin.
Reset: Counterweight re-arms on a 1-minute cycle unless spiked.

Drop: 25 ft vertical into L2-28, landing due west of the Maw-Well (10-ft gap).
Fall Damage: 2d6 bludgeoning (reduce by slow-fall features as normal).
Landing Surface: Cracked ruby plates on a subtle down-grade toward the well.

Landing Save: Each creature must make a DEX save DC 12 or land prone and slide 5 ft toward the Maw-Well (stop at the lip). On a success, land crouched in place (no slide).
Gear Scatter: Unsecured item (DM’s pick) has a 50% chance to skitter toward the Maw; on a 1 on d6 it topples in.

Noise & Wrath: The chute’s slam and the impact advance the Tremor Clock by +1 (by +2 if 3+ creatures fall at once). If this raises the clock to Tick 4, Maw-Primed begins immediately next round (see Grasp of the Maw).

The Shrine (40′ × 40′)

Ceiling: 15–18 ft, basalt “ribs” (two are shattered and lean).
Floor: Plate-broken red tesserae over voids (see Narthex effect below).
Centerpiece: Split Black Altar pouring toward the Maw-Well (vertical, 10-ft throat; cold exhale).
Icon: Obsidian Eye of Beltar set in the altar’s shadow (see Reliquary).

Zonal Details

• Narthex (west 10 ft): Fractured plates over hollow. Difficult terrain. Any dash/violent action → DEX save DC 12 or foot punches through (speed −10 this round). Fail by 5+: drop 10 ft into rubble pocket (1d6, prone).
• Nave (middle 20 ft): Two leaning ribs; passing between them at more than half speed risks falling shard (DEX save DC 13; 1d6 piercing).
• Sanctum (east 10 ft): Split altar over the Maw-Well; cold draft; faint out-of-measure pulse felt in teeth.

Reads:

• Religion DC 12: Beltar pit-rite—offerings cast into the deep; the split marks divine retribution.
• Stonecunning/Geology DC 12: The throat is a fault chimney dropping 20–30 ft before grinding along a chute into deeper caverns.

Tremor Clock

Tremor Clock (4-tick, starts at 1 on entry)

Advance +1 when any of the following occur: a shout or loud metal-on-stone clang; thunder damage; a strike upon the altar/ribs; iron scraped across ruby inlay; Beltar invoked in anger.
Advance +2 (instead) if blood or iron is dropped into the Maw-Well, or if an appeasement attempt fails.

Passive decay/cooldown: Each full minute with measured whispers (no raised voices, no metal scraping) reduces the clock by 1; stepping out of the chamber for 1 minute also reduces by 1 (minimum 1).

Tick 1 — Sullen Beat

A faint, off-measure throb pervades the stone. Stealth checks in the shrine and approach corridor are at −1 unless feet are wrapped/soft-soled. (No save.)

Tick 2 — Dust Fall

Powdered grit sifts from the ribs and seams. Each creature must make a CON save DC 10 or suffer disadvantage on Perception (hearing) checks for 10 minutes (gently clogging ears and nostrils).

Tick 3 — Floor Buckle

Choose a 10-ft square in the Narthex; it slumps 3 ft (treat as a half-pit, difficult terrain). Creatures entering or fighting in that square must succeed on a DEX save DC 12 or fall prone.

Tick 4 — Stone-Spite Pulse (and Maw Primed)

Basalt ribs shudder; razor chips burst from seams. Each creature must make a DEX save DC 14 or fall prone and take 1d6 piercing from slivers.
After this pulse, the shrine becomes Maw-Primed until appeased or vacated for 1 minute:

• At initiative 20 (lair) each round while Maw-Primed, resolve Grasp of the Maw: every creature within 20 ft of the well must succeed on STR (Athletics) or DEX (Acrobatics) DC 15, or be dragged 10 ft toward the lip; fail by 5+: dragged to the lip and knocked prone (topple if already at lip). Anchored creatures (roped/pitoned) have advantage; heavy armor imposes disadvantage.
• Each subsequent round the DC increases by +1 until appeased or the party leaves the chamber for a full minute.
• If Maw-Primed persists for 3 consecutive rounds or blood+iron are offered to the well, the shrine summons an Underdark hunter up the 10-ft shaft on the following round (DM: choose CR by tier; e.g., carrion crawler, grell, cloaker, black pudding).

Reset: If no further triggers occur and the chamber is left for 1 minute (or appeased—see below), reduce to Tick 2; otherwise remain Maw-Primed.

Appeasing the Shrine (soothing the stone)

Perform the six-count canticle: tap the altar’s four corners in measured six with one beat of silence, lay a ruby chip or red glass across the split, and keep iron from the stone.

• Check: Performance DC 11 or Religion DC 12 to suss and keep cadence.
• Success: Reduce the clock by 2 (minimum 1), end Maw-Primed, and suspend hazard advances from normal speech for 1 hour.
• Failure: The clock advances +2 immediately as the measure falters.

Tips (player-facing aids): Wrapping boots, padding tools with cloth/leather, and coordinating whispers can help avoid triggers; invoking order/warding magics respectfully during the rite grants advantage on the appeasement check (DM’s call).

DM Notes: The Maw-Well

(1000-ft drop to the Underdark)

Profile. A 10-ft-wide vertical shaft—the Maw-Well—falls roughly 1,000 ft through faulted stone to a junction of deep galleries and river tubes (Underdark arteries: drow/duergar patrol zones, carrion vaults, blind-fish rivers). A constant cold updraft rises, carrying distant drip and the reek of lichen-rot.

Falling.

• If a creature goes over the lip, it falls. Treat as RAW falling: up to 20d6 bludgeoning on impact (terminal damage cap). The shaft includes two jag-toothed ledge bands at ~150 ft and ~420 ft where a falling creature has a fleeting chance to catch or be gouged.
• At 150 ft: DEX save DC 14 to catch a knife-ledge (take 4d6 from the catch success halts the fall clinging, prone, at disadvantage to climb without gear. Fail: continue.
• At 420 ft: DEX save DC 16 to catch (take 6d6 from the catch). Fail: continue to terminal.
• Thrown line: A secured rope hurled within 10 ft of a falling ally allows a reaction: ally makes DEX (Acrobatics) DC 14 to grasp. The thrower must win a STR contest vs. the fall (assume +5 for mass and momentum) or both go over the lip (the thrower has advantage if braced with pitons or a hammered spike).
• Items & light: On a fall, any unsecured metal or lantern has a 50% chance to skitter off into the shaft immediately; if it goes, its clatter advances any shrine hazard clock you are using by 1.

Climbing the shaft.

• Smooth stone, wet edges: Athletics DC 16 without gear; with pitons/grapnels: DC 12. The cold updraft imposes disadvantage on checks made while exhausted or sapped of temp HP.

Beltar’s Wrath: When the Maw Pulls

When certain offenses are committed—iron bled upon the altar, divine wards of “order” cast in scorn, the Eye pried with metal, or Beltar’s name shouted in challenge—the shrine answers. The cold updraft reverses, the ruby plates shiver, and a crushing downward mood grips the chamber:

The Grasp of the Maw (Lair-like Action, initiative 20).

• Every creature on the shrine floor within 20 ft of the well must make a STR (Athletics) or DEX (Acrobatics) save, DC 15 (choose). On a failure, the creature is dragged 10 ft toward the well; on a failure by 5+, it is dragged to the lip and knocked prone (if already at the lip, it topples).
• Creatures anchored by hammered pitons or a tied, secured line have advantage. Creatures in heavy armor have disadvantage.
• Each round this persists, the DC increases by 1 (the room’s fury mounting) until the party appeases the shrine (ruby tithe + six-count hush) or leaves the chamber for a full minute.