An ancient abomination born of forbidden ritual sleeps beneath Vermouth’s Great Cathedral — fed by a fanatical high priest who calls it a god of purification and a warlock who has grafted himself into its living flesh — and unless the heroes descend into its digestive depths and end it, the city above will be consumed from within.
Welcome to “The Maw of the Cube” 5E adventure! Within these pages, you’ll discover everything necessary to embark on this thrilling quest, complete with detailed descriptions of locations, encounters, NPCs and stat blocks, maps, and handouts.
This adventure also features a versatile and scalable system, allowing Game Masters to easily adjust the difficulty and complexity of encounters to suit their players’ preferences and skill levels. Whether you have a party of advanced players or beginners, you can tailor the challenges to ensure an exciting and engaging experience for everyone involved. The scalable system guides modifying creature statistics, making it simple to customize the adventure to fit your party’s level.
In “The Maw of the Cube,” a party of 3-5 characters (levels 5-7) arrives in plague-stricken Vermouth, where robed zealots drag the sick beneath the Great Cathedral for “cleansing” — never to return. The culprit is the Maw, a colossal sentient ooze created by the long-dead Ossuary Pact and dormant for generations beneath the city’s foundations. High Priest Gellert Vorne discovered it, mistook it for a divine being, and has been feeding it plague victims. Meanwhile Malakar the Hungerer, an exiled warlock, has forged a pact with the awakening creature and fused himself into its living tissue, guiding its hunger toward conquest. The heroes must navigate the city’s chaos, descend through three levels of increasingly organic dungeon, and face a final confrontation at the Maw’s pulsing Heart — where destroy, bind, or be consumed are the only paths forward. The adventure is divided into three acts.
Act 1: The Rotting City
Vermouth teeters on the edge of collapse — riots in the streets, plague pyres burning, robed zealots chanting as they haul the sick toward the Cathedral, and a plague that the party itself is not immune to. Several key locations define the city: a quarantined gate that must be talked, bribed, or slipped past; a square where the party faces an immediate moral choice as zealots move to seize a feverish child; a ruined apothecary hiding both a horror and the first proof that the plague is no act of nature; streets that erupt into full riot just before the Cathedral, offering several routes through; and the Cathedral of Vorne itself, where the moment the party crosses the threshold the doors boom shut and a rhythmic heartbeat rises from below.
Act 2: Descent into the Maw
The dungeon spans three levels, each more organic than the last, as stone gives way to flesh and then to active digestion. The False Ruin is a level of psychological dread — a hall that traps the party the moment they enter, a puzzle of vanishing doors, attacks from the remnants of those the Maw absorbed before, and a voice that speaks directly into the mind with no body to strike at. The Flesh Tunnels drop all pretense of stone, pushing endurance and creativity through contracting passages, pools of acid, treasures embedded in living tissue that punish greed, and a pulsing bridge of hardened tendon — and it is here that Malakar first appears, half-fused with the dungeon, to offer a bargain before withdrawing. The Digestive Chamber is openly hostile, a gauntlet of toxic fumes, constricting corridors, a staircase that crushes like a serpent, and a chamber of hundreds of watching eyes, all leading to a final guardian at the threshold of the Heart.
Act 3: The Heart of the Maw
The Heart chamber is a cathedral of living flesh — bone ribs overhead, acid weeping from the floor, a bioluminescent gloom thick with psychic static. High Priest Vorne awaits with arms outstretched, only to be seized and consumed before the party can intervene — proof that even the Maw’s most devoted servant is just another meal. Malakar then reveals himself as the true antagonist and calls on the creature’s full power for the final battle, a fight that escalates as he merges further into the Maw itself. A party that has gathered the right tools along the descent has an alternative to open combat: a ritual path to bind the creature rather than destroy it. Three endings decide Vermouth’s fate — destroy the Maw and scar the city forever, though a retreating sliver may hint the horror is never truly finished; bind it and leave the party as the uneasy dark guardians of a pacified ancient hunger; or fail, and watch the Maw consume Vermouth within days, launching a far larger campaign to stop it before it spreads.
Release Date: 2025 Format: Digital (PDF)
Items Included
- The Maw of the Cube 5E (PDF)
- A B&W Printer-Friendly Version (PDF)
- Maps
- Illustrations (Generated with Midjourney)
- Monster Stat Blocks
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