See my review of Hall of Harsh Reflections. Level 7–8. Dungeon #127 PDF | Paizo Supplement | Dragon #336 Wormfood

Foreword

Most of this post is written by AI. I’ve invested quite a bit of time in building an llm-wiki for the Age of Worms campaign, to the point where if I read the adventure, I can use AI to competently write a prep document. It’s 85% as good as what I could do, but in 5% of the time. I’ve lightly edited the entire post for accuracy and corrected bad mechanics everywhere I found them, as well as the most common style fixes. You will also see “My notes” sections when I want to call out something I would change or handle with care.

Outline

Journey to the Free City
Welcome to the Free City (Scenes 1–6)
Betrayal at the Bar (Scene 7)
Sodden Hold — Telakin’s doppelganger stronghold
Zyrxog’s Domain — the mind flayer’s lair

Free City of Greyhawk map: Maldin’s Greyhawk — The City of Greyhawk (high-res annotated map, cross-referenced with the Age of Worms-era Dungeon #128 “Midnight’s Muddle” article)

Journey to the Free City

85 miles from Diamond Lake, roughly 5 days through hills. Journey rules: 10% encounter chance per check, 2 checks per day (one day, one night). No guards or a failed DC 15 Wisdom (Survival) check raises the night chance to 20%. Cap it at 2 encounters total.

Travel encounter table:

Bandits — 1d3+3 human rogues demanding exorbitant tolls. Flee if one is slain. Use Bandit Captain + 4 Bandits.
Trolls: Murnk & Nathk — two brothers seeking revenge on adventurers who raided their lair. Surviving troll begs for its life, offers 87 sp + 1 gp. Use 2× Troll.
Owlbears — a pack of 1d4 + 1 owlbears stalking the road, pounces on stragglers, breaks off at half losses.
Worgs — 2d6+2 pack predators, break off at half losses.

Welcome to the Free City

Perched on the banks of a broad, slow-moving river, the glistening Free City comes into view. Tall spires and gabled roofs crowd together and peek out over the high stone walls. Scores of common folk, along with carts and wagons laden with wares, form a long line slowly trudging toward the nearest gate.

Scene 1 – The Gate

Two-hour wait in line, then inspection. City law bans contraband (destructive magic, drugs, poison). A DC 15 Charisma (Deception) check bypasses it; otherwise, PCs in good gear get shaken down.

“Well what do we have here? Fancy folk here to spend their coin in the Free City. Well, what’s your business here? And be prepared to turn out your pockets.”

Harl Benvek (“Harl the Helpful”) — veteran spearman, friendly bureaucratic tone, implies extra fees “to avoid delays.” Knows just enough city ordinances to sound legitimate; quotes fines that don’t actually exist. Prefers small, quick bribes (1–5 gp per head). Backs off if confronted confidently, and will quietly warn PCs about other crooked officials if paid. Coward at heart — folds immediately if authority or violence seems likely.
Merris Talonhand — younger, sharp-eyed guard playing the heavy, watches reactions closely. Signals Harl when PCs look wealthy, foreign, or distracted. Enjoys escalating with threats of inspections, confiscation, or “holding cells.” Carries a ledger with falsified entries. If exposed, tries to pin everything on Harl.

DC 13 Wisdom (Insight) check reads the bribe-fishing. Actual contraband: confiscated + 20 gp fine per dose. PCs who protest forcefully and repeatedly get let through.

Scene 2 – Parade of Thieves

A parade celebrating the upcoming Champion’s Games. A chimera (blue dragon head) is caged on a wagon — it’s been slowly weakening the iron bars with lightning breath through the glass panes.

Argen & Sald (2× Spy) — working the crowd as pickpockets. DC 15 Wisdom (Perception) check to notice you’re being robbed. If spotted, they fight; if the chimera breaks free first, they flee. Bump to Assassin (CR 8) if the party is strong.
Chimera (CR 6) — breaks free moments after the rogues ply their trade. Wings clipped (can fly but must land at end of movement). Attacks the nearest target; a small child left behind is an easy target if the party backs away. Blue dragon head reskin: Lightning Breath (Recharge 5–6). DC 15 Dexterity save, each creature in a 30-foot Line, 5 feet wide. Failure: 45 (10d8) lightning damage. Success: half damage.
The watch captain appreciates the party’s help with the escaped monster. Killing Argen or Sald draws a warning that vigilantism won’t be tolerated.

Scene 3 – Rain Barrel Man

Noncombat flavor. A balding man in a ratty robe stands on a covered rain barrel, ignored by passersby.

“Listen to me, you children of the Free City, and hear the doom that builds before your blind eyes. Have you not heard the dead dragons roar? Have you not smelled the rot festering under your very nose? Have you not dreamt of the worm that walks, bringing decay to all he touches? Fools, you are all fools! Your doom is upon you! The end is in sight and none of you shall be spared. Decay is the future and the future is here!”

Calls himself “the prophet of the golden eye.” Won’t answer questions — just stares. Last week he was shouting about “the dragons of the rift.” He’ll repeat the rant endlessly but knows nothing more when questioned.

Scene 4 – Eligos

Located in the Garden District. Manservant Pollard (aged male elf) opens the door and escorts the PCs to a velvet parlor with fine wine and fruit.

A middle-aged man wearing an open red robe with a silver breastplate underneath enters. His eyes are sharp wells of deep gray accented by specks of red. “My manservant tells me that you wish to speak to me. My name is Eligos. How can I be of assistance?”

Eligos (archmage) — patient, level-headed, respected sage. Old apprentice of archmage Manzorian (aka Tensor); now one of Manzorian’s chief agents in the Free City. Patient but doesn’t suffer fools.

On Allustan: “Hmm, I never thought I would hear from him again. But nonetheless, please continue.” Warms up once the connection is established.
Items he wants to examine: Zosiel’s silver diadem, the two demon horns, the talisman of the sphere, the jar with the green worm.
What he’ll research: the Ebon Triad, the spawn of Kyuss, Age of Worms lore. Takes about a week. Needs to keep the items.
Payment: none if Allustan is mentioned; otherwise “future considerations, nothing dangerous.”

“Although not my area of expertise, I do know a bit of what you speak and am greatly disturbed. I will look into this matter, but it will take some time. I should be able to gather the information you seek within the week. While you wait, might I recommend that you stay at the Crooked House in the Foreign Quarter? Mention my name and he’s sure to give you a discount on rooms.”

Scene 5 – Night on the Town / Blueberry Theatre

The Blueberry Theatre is a playhouse well known for mocking the Free City’s officials and politicians — an excellent source of local gossip and rumor. Run by Madame Goschild. Good location for downtime RP and information gathering between events.

Scene 6 – Crooked House

Foreign Quarter inn and tavern run by Tarquin Shortstone XXIV (NG male gnome). The building is literally off-kilter — walls at odd angles, no right angles, a treacherous shifting staircase.

Rooms: 6 sp/night (includes morning meal); 4 sp/night + free drinks if the party mentions Eligos.
Taproom decorated with owlbear heads — Tarquin’s pride and joy.
Locals stop in nightly after closing their shops — good RP hub and rumor source.
Eligos and Tarquin are old friends who meet weekly for dragonchess.

Betrayal at the Bar

Occurs 3 nights after the PCs arrive. Telakin’s doppelganger agent Elaxan makes his move.

The setup: Elaxan (disguised as a simple merchant) goes upstairs, assumes the form of a sleeping PC, comes back down and stabs Tarquin with a dagger, then drinks a potion of invisibility. Tarquin drops to -1 HP, bleeding behind the bar.

Crowd mechanics: Elaxan tries to get out of eyesight and change into a merchant who blames the party. He uses an opposed Charisma (Persuasion) check to try to turn the 14 patrons hostile. Initial attitude: Unfriendly. Either side winning by 5+ shifts the attitude one step. Each check takes 1 minute — sleeping PCs have time to come downstairs.

Elaxan → Doppelganger Assassin (MME, CR 8)
14 Tavern Patrons → Thug × 14 (CR 0, MM 345), armed with knives (1d4), bottles (1d4), or chairs (1d6). Tarquin discourages armor/weapons in the taproom.

Key development: Elaxan’s pouch contains a crooked iron key — the head bears a ship being pulled underwater by a huge octopus. DC 20 Intelligence (Investigation) check, or DC 15 from informants, traces the mark to a now-dead merchant who owned River Quarter warehouses — one still stands: Sodden Hold.

If Elaxan is killed, he reverts to his true form and automatically clears the PCs of all charges. If the PCs are arrested, they’re stripped of gear and held overnight — doppelganger agents inside the watch deliver them to Sodden Hold the next morning (split party, gear confiscated, delivered straight to D5). If Tarquin survives and the PCs prove their innocence: free room and board for a month.

***My notes: This is hard to pull off. You really have to steal some character agency to make this go easily. It’s okay if your group can roll with it, but if they usually don’t (or this isn’t a group you know well) I would go ahead and have the doppelganger impersonate a present character and just lower the Persuasion DCs by 5 since it’s much easier to prove it wasn’t a PC. ***

Sodden Hold — Telakin’s Doppelganger Stronghold

Down by the river outside the city walls, in the warehouse district. Stone building with a moss-covered roof, faded green “Sodden Hold” signage. Lit by everburning torches (30 ft. ceilings). Superior masonry walls, strong wood doors throughout.

Warehouse Level

D1. Entry — Iron double doors, good-quality lock (DC 17 Thieves’ Tools; Elaxan’s key also works). DC 15 Wisdom (Survival) check reveals the doors are used frequently despite the abandoned look.

D2. Storage Hall — Large space with crates and barrels (cheap goods). Two locked doors south, trapped false door north. Catwalk runs along the east side, 15 ft. up, with two doors: south one unlocked (→ D4), north one hidden (DC 16 Wisdom (Perception) check). Two mimics and a greater mimic (MME) disguised as crates/barrels — DC 16 Intelligence (Investigation) check to identify. False north door trap: wide-mouth spiked pit, DC 17 Dexterity save or fall 40 ft. (4d6) plus spikes (+10 to hit, 4 attacks, 1d4+5 each); DC 17 Wisdom (Perception) check to detect, no check to disable.

D3. Abandoned Office — Locked (DC 17 Thieves’ Tools). Old ledgers and papers from a business that closed 10+ years ago. 10 minutes + DC 17 Intelligence (Investigation) check finds a ring of swimming the doppelgangers accidentally left behind.

D4. Rickety Ladder — Connects ground to the catwalk (D2). Climbing it collapses the ladder and brings catwalk debris down — 2d6 damage to everyone adjacent, DC 15 Dexterity save halves.

D5. Storage Cell — Reached via the hidden catwalk door. Staircase down to an oblong chamber with unlocked chests: Ilya’s chest (periapt of health, signet rings, a 200 gp sky blue cloak), Gattel’s chest (bag of holding containing 863 gp), and — if the party was captured earlier — the PCs’ own gear.

D6. Cells — Five cells, iron bar walls, everburning torches, average locks (DC 15 each).

Cell A — Ilya Starmane (LG elf aristocrat 4): abducted about a month ago, family unaware. Cold and distrustful — the doppelgangers have been toying with her. Minor noble, key trade link to Celene. Rewards rescue with her periapt of health.
Cell B: empty.
Cell C — Gattel Watam (CN human, former tax collector): captured two years ago, mind shattered by a failed mind-clone procedure. Cycles between weeping, childish laughter, and haughty noble talk; occasionally lucid enough to name himself, usually followed by an attempted suicide. Kept alive because the doppelgangers still need to impersonate him to collect funds.
Cell D: empty (blood-soaked straw).
Cell E — “Martal” and “Regim” — claim to be captured town guards, describe horrible experiments. Hidden latch opens the cell from inside; gear hidden under the straw mattress. Actually 2× Doppelganger Dark Whisperer (MME) — beg to be released, attack the moment the door opens.

D7. Coll Chamber — Floor has fallen away over a stagnant pool full of rusted spears and broken swords. Crossing the soggy timber planks: half speed, DC 15 Strength (Athletics) check; fail by 5+ and fall into the weapon-filled pool. Shaded planks have an unsound piling — any medium or larger creature triggers a collapse. Falling in triggers weapon attacks (+10, 1d6+4, once per 10 ft. of movement through the water). Saying “deception” before crossing lets you pass unchallenged. Exit door locked (DC 15), out of sight when entering. Two invisible stalkers attack once PCs step onto the planks, and target anyone trying to fly or bypass them; a hit forces a DC 12 Dexterity (Acrobatics) check to avoid falling. DC 15 Wisdom (Perception) check spots corpses in the water; DC 15 Intelligence (Investigation) check finds a Figurine of Wondrous Power — Onyx Dog among the bodies.

D8. Water-Filled Pit — Two holes: a ragged tear (to the stagnant river pool) and a square, water-filled shaft (35 ft. deep, wooden barrel on the surface, crude rope ladder down). Metal armor sinks you to the bottom in 2 rounds; otherwise DC 10 Strength (Athletics) check to swim at half speed. A 20 ft. passage west at the bottom leads to D9 (also flooded, dark, very salty). The lever to control the water is in D9 — you have to get wet first.

D9. Water Control Chamber — Central stone pillar rises 10 ft. above the waterline, metal ladder to the top. A lever opens floor drains, emptying the room at 4 ft./round (one full minute); tripping it again refloods the room. Locked door on a stone platform 50 ft. up (DC 17). A Giant Squid (MM, CR 6) — Zyrxog’s experimental gift to the doppelgangers — escapes via the drains when the water lowers and returns when it floods. A hidden passage in one wall (DC 20 Intelligence (Investigation) check, found automatically later) leads to the Free City sewers and Zyrxog’s domain.

Warren Level

Meticulously kept, no dust, walls carved with intricate scrollwork that never repeats. Pale blue everburning torches, iron doors.

D10. Hallway — Long hall, iron double doors at each end, four locked doors south (DC 17 each), one north. Noise here summons the six doppelgangers from D11 to investigate. Trap: the apparent east door is a 10×10 ft. trapdoor over an illusory wall (CL 11) 30 ft. down that creates a false floor — the real floor is 60 ft. down in a magical silence zone, so victims appear to just vanish. Walls smooth and greased, impossible to climb. DC 15 Dexterity save or fall 60 ft. (6d6) plus spikes (4d4).

D11. Doppelganger Bedrooms (×3) — Each packed with outfits of every style (the doppelgangers practice disguises), two doppelgangers per room, back from operations in the city. 6× Doppelganger (MM 82, CR 3). On a general alarm, all six mobilize in D10 to intercept anyone heading toward D13 or D9; survivors retreat to D16. Treasure: 500 gp in jewelry across all three rooms, plus 250 gp in noble/royal outfits.

D12. Lavatory — Nothing of value.

D13. Planning Room — Two tables buried under maps, notes, and books; a large map of the Free City on the far wall. 2 hours + DC 15 Intelligence (Investigation) check reveals the full scope of the doppelganger conspiracy — noble families, merchant councils, the leatherworkers’ union, carpenters’ guild, stonemasons, courts, militia, and the directing oligarchy, all infiltrated. Names are deliberately omitted from the documents. Hidden door in the SE corner behind a bookcase (DC 20 Intelligence (Investigation) check) leads to D16. Handing the documents to authorities is worth 1,000 gp and the goodwill of important city figures.

D14. False Bedroom — Looks like D11 but no jewelry. East wall is an illusory wall (Study action, DC 16 Intelligence (Investigation) check to disbelieve) hiding a small dark chamber; the iron door beyond is unlocked and leads to D15.

D15. Hall of Deception — This is the room the adventure takes its name from.

The walls of this tall octagonal chamber are mirrored with a dark black glass reflecting ghostly blue flames from a trio of torches suspended above. In the center of the room is each one of you, manacled and tied to a chair, struggling to escape.

If you decided to use a captured PC replaced by doppelgangers, that PC is here (bound in manacles, DC 17 Dexterity (Acrobatics) or Strength (Athletics) check to break free), plus one doppelganger per other PC, all in the PCs’ likenesses. The doppelgangers’ manacles are rigged so they escape automatically. They free themselves one at a time, rush to “embrace” their matching PC, and accuse the party member of being the fake — once in melee range, they attack. If the deception is foiled early, all doppelgangers attack at once.

Ixiaxian (Doppelganger assassin, MME) — the spy possibly embedded in the party. Reveals himself here, attacking the most vulnerable PC. The player immediately resumes their actual manacled character.
Variable doppelgangers (1 per non-replaced PC): 22 HP each, with the Haunting Similarity feat (advantage attacking the PC they’re emulating). Use one Doppelganger Assassin, one Doppelganger Warlock, one Doppelganger Dark Whisperer, and normal doppelgangers for the rest.
Treasure: Ixiaxian carries the duplicated PC’s gear plus a mind-clone sapphire (2,000 gp — an encoded copy of the PC’s memories, accessible via detect thoughts).
If no PC was replaced beforehand, swap this room for 4× Aranea in a chamber full of silvery spider webs. ***My notes: I wouldn’t skip this encounter, and the araneas will make little sense. This is a great spot to actually swap out a PC ahead of time if you want the reveal to land — I did this in my own game and it worked, though it’s a heavy-handed move you should telegraph as being in service of the scene, not a “gotcha.” ***

D16. Mirror Maze — Floor-to-ceiling polished metal mirrors forming a labyrinth of reflections. Pressure-plate walls: squares flanking dashed lines on the map have pressure plates; triggering both simultaneously raises a mirrored wall instantly (DC 25 Dexterity save to dive through before it closes). A hidden floor switch (DC 20 Intelligence (Investigation) check) or DC 20 Thieves’ Tools lowers the walls again. 3× boosted Doppelganger Guard (78 HP each, potions of invisibility) — two use invisibility to flank and attack, the third warns Telakin in D17 then rejoins. They know all the wall locations and use them to split the party, taking party members’ forms once their invisibility ends. My notes: I skipped this encounter.

D17. Telakin’s Hall — Vaulted chamber. West wall holds a macabre mind-clone apparatus (vats, tubes, silver helmet-table); the far side has a raised dais with a throne.

Mind-clone device: a strapped-down victim (10 minutes, DC 20 Wisdom save to resist) has a mind clone created in a gemstone (minimum 2,000 gp). The clone is accessible via detect thoughts as if contacting the real person.
Telakin (Doppelganger) appears as Allustan (or Eligos, only if the PCs don’t know Allustan). Starts as an Archmage; when dropped to 0 HP, transforms into a Berserker Commander with full hit points.

“So kind of you to join me. It is time for me to show you the truth of things. Come and learn what lies beyond!”

Traps (4 total): two wide spiked pits in front of the throne stairs (DC 15 Dexterity save or fall 40 ft., 4d6, plus spikes; DC 20 Intelligence (Investigation) check to spot), and two poisoned ceiling spears on pressure plates at the top of the stairs (+7 to hit, 1d8+4 plus scorpion venom, DC 14 Constitution save or poisoned for 1 hour; DC 20 Intelligence (Investigation) check to spot).
Treasure: two locked containers near the device (DC 17 Thieves’ Tools) each hold a mind-clone gem (2,000 gp) — Syra Viniira (a foppish wine/etiquette expert) and Durgan Shatterhelm (a militia captain who knows all the watch routines). Both subjects are dead, bodies in the pool above. Telakin wields a Frost Brand Greatsword in his berserker form.
After Telakin falls: a DC 20 Intelligence (Investigation) check of the throne reveals a hidden button that opens D18. His key ring opens every room in Sodden Hold.

D18. Telakin’s Sanctum — Bed, wardrobe (every outfit style plus 500 gp in jewelry), desk, a shifting geometric rug (500 gp, cosmetic only). A magic mirror (10,000 gp, 250 lbs) reveals the true physical form of any shape-disguised creature in the room once per day for 10 minutes — can’t penetrate illusions; Telakin liked to use it to admire his own true form. Locked chest (DC 20 Thieves’ Tools, or Telakin’s key ring): forged and original Free City documents showing the scope of the infiltration, a scroll of dominate person, 1,500 gp, and Zyrxog’s missive:

“I have a task for you, thrall. Meet me at the sewer junction beneath the cold forge and I will give you the details. There are some troublesome small minds that must be removed.”

Signed with a spiraling tentacle symbol — the same mark on Telakin’s forehead tattoo and the columns in the museum (M11).

Zyrxog’s Domain — The Mind Flayer’s Lair

After Telakin falls, Zyrxog — watching through his scrying pool — comes through the now-open secret passage in D9 with 2× Drow Elite Warrior (Adventures in Faerûn). He opens with Mind Blast, then lets the drow handle the fight and flees via plane shift if personally threatened. The drow fight to the death.

Trail to Zyrxog: phosphorescent fungus on the drow’s boots is Beggar’s Gold, a rare underground fungus. DC 15 Wisdom (Nature) check identifies it as growing near forge/smithy runoff in underground urban environments. DC 15 Intelligence (Investigation) check locates the source: the Cold Forge smithy in the Artisan’s Quarter, whose owner Crusty Patten has no idea what’s under his shop. Sewers from any street grate to the Cold Forge junction are 10 ft. wide, up to 3 ft. deep brackish water, difficult terrain, a maze of chambers and cisterns — DC 10 Wisdom (Survival) check if following the trail. A large patch of Beggar’s Gold marks the entrance: an ancient, particularly deep (60 ft. underground) sewer tunnel off the main line.

Drow Caves

Natural cave complex, 20 ft. ceilings unless noted, unlit, unworked stone, difficult terrain on uneven floors.

ML1. Fungus Cavern — Large chamber covered in phosphorescent fungus and giant toadstools. Yellow mold (cultivated by Zyrxog) in the center, DC 17 Wisdom (Nature) check to tell it apart from Beggar’s Gold — disturbing it releases spores in a 10 ft. radius (2d10 poison, DC 15 Constitution save or poisoned 1 minute, plus 1d10 poison each turn until a repeated save succeeds; destroyed instantly by fire or sunlight). 4× Shrieker Fungus (MM 138, CR 0) scream if light or a creature comes within 10 ft. — audible throughout the whole complex, warning all the drow.

M2. Drow Sentries — Corridor sloping toward M3, running water audible ahead, a ledge 10 ft. up leads to a hidden alcove. If warned by the shriekers: 3× Drow Elite Warrior (Adventures in Faerûn 260, CR 5) coat the floor with flammable oil and throw alchemist’s fire to ignite it (1d4 fire, 2 rounds; DC 15 Wisdom (Perception) check to spot the oil first; DC 17 Strength (Athletics) check to reach their ledge). If not warned, they’re reclining quietly.

M3. Spirit Pool — A large chamber dominated by a pool glowing pale green. Fassash (Spirit Naga, MM 234, CR 8) is friendly with Zyrxog but not under his control, coiled near the pool; the drow avoid this room and travel along the west wall instead. Fassash wants proper deference, an apology for disturbing him, and at least 1,000 gp in treasure to let the party pass without incident. With a DC 20 Charisma (Persuasion) check plus sufficient pampering he will offer cryptic hints about what’s ahead. Pool treasure at the bottom: 8 pp, an emerald (200 gp), and a crystal jug that’s actually an eversmoking bottle.

M4. Drow Enclave — Vast chamber, 40 ft. ceiling, a shelf 20 ft. up used for sleeping, a livestock pen (half-starved cow, pigs), a gated corridor south to M5. Myrianaas (Drow Priestess of Lolth, CR 8) plus 5× Drow Elite Warrior (CR 5). If warned, Myrianaas places three drow front line and two on an elevated crossbow flank, and flees to M7 if sorely pressed to warn Zyrxog. Treasure: a small jade Lolth statue (300 gp) in the sleeping caves’ shrine.

M5. Chattel Pen — Iron bar wall floor-to-ceiling, iron door locked (Myrianaas has the key; otherwise DC 15 Thieves’ Tools). 4× Zombie (MM 316, CR 1/4) stand just inside, ordered to prevent escapes, not stop entries — they attack if the party tries to leave the room or attacks them; this fight can be hand-waved. Beyond: debris, straw, filth, and five prisoners in dark side corridors (2 merchants, 1 elf craftsman, 2 young women) too afraid to attempt escape on their own, but who’ll flee immediately if helped past the yellow mold. My notes: Zombie fight is worth skipping.

M6. Warding Glyph — Widened corridor, smoothed floor, a large glowing purple symbol on the floor that’s a permanent illusion and harmless domain boundary marker. The real danger is a Glyph of Warding on the ceiling that triggers on any non-evil creature passing beneath (detect magic or DC 18 Wisdom (Perception) check reveals it): 6d8 acid damage to everyone within 15 ft., DC 14 Dexterity save for half.

M7. Tentacle Guardians — Tall white marble double doors with purple-veined streaks, ivory columns flanking them bearing Zyrxog’s tentacle seal, barred from inside (DC 20 Strength to burst, Hardness 8, 120 HP). 3× Octopin (use a Chuul reskin, MM 40, CR 4 — see the conversion note below) hide near the ceiling behind columns and stalactites, using their gaze to monitor the doors without revealing their position, then surprise the party from all directions when they approach.

M8. Stone Brain — Domed chamber with a large brain carved from purple-veined white marble in the center, veins appearing to pulse; four stone benches with iron manacles. The brain communicates telepathically — it’s a sentient magic item carrying Zyrxog’s personality, and relays to him if within a mile. Auto-reset trap, once per round: targets one creature within 15 ft., DC 17 Wisdom save or Dominated (loyal to Zyrxog, hostile to the party). Hardness 8, 50 HP — destroying it frees anyone dominated.

M9. Laboratory — Bookcases, a desk, a large open-top tank of green liquid, a stone door (unlocked) to M10. The bookshelves hold anatomy/arcane fusion texts worth 1,000 gp to a shady collector or 500 gp to a respectable dealer. The desk has logs on octopin creation plus notes on a new “mind worm” parasite project (hosts susceptible to suggestion). An Advanced Octopin (boosted Chuul, roughly CR 10, 136 HP) hides in the murky tank and crawls out when disturbed — 2× tentacle claws +19 (2d6+8), Rend (4d6+12), Slowing Gaze (DC 18 Constitution save or speed halved and disadvantage on attacks until the end of the next turn). Immune to lightning.

M10. Viewing Pool — Small round chamber, a perfectly calm pool glowing pale blue, green light flowing in from the hallway opposite. Zyrxog’s clairvoyance pool: sit on the bench and concentrate to view any well-known location within 5 miles (as clairvoyance); unknown locations leave the pool dark. Currently showing Telakin’s throne room. The opposite hallway leads to a narrow balcony 45 ft. above M13’s floor with no apparent way down.

M11. Museum — A central ebony vrock statue surrounded by glass display cases of dark artifacts:

Case 1: a preserved juvenile black dragon head (eyes glow green), an empty black thorn-cage, a +2 unholy dagger (brings misfortune, DM’s call), and a kyton’s twitching chains.
Case 2: four blank “unspeakable tome” books hiding a vacuous grimoire, a fiendish bronze griffon figurine of wondrous power (attacks the wielder when used), and four preserved beholder eyestalks.
Case 3: a petrified pseudodragon, a stuffed PC-lookalike doll with 20 spikes (strong necromancy, no apparent effect), and an animated chained book that attacks anyone nearby until slain (it lists 100 demon names).

A Vrock (MM 64, CR 6) is bound as the central statue and releases if the statue or any case is disturbed.

M12. Hallway — Slopes down 30 ft. to M13. Walls painted with a long frieze depicting mind flayers marching across the sunless surface world, all races of the surface bowing before them.

M13. Cathedral of the Mind — 80 ft. ceiling. A tall octagonal jet-black column glows with green symbols above a deep pool of placid green liquid holding mind flayer tadpoles (harmless, years from maturation — worth 1,000 gp to a shady dealer, or 2,000 XP as a reward for destroying them all). The unhallow effect on the column gives evil creatures +2 to saves and AC against good creatures, plus fire resistance 20.

Floating above the pool is a humanoid form with strange rubbery purple flesh, dressed in black robes, wielding a staff of red-hot metal. Its head is hairless and bulbous, with four long tentacles where its mouth should be. Inside your head you hear an alien voice: “You dare enter my sanctum! Fools. I shall finish what Telakin could not. Your weak minds will be a sumptuous feast, your terror a pleasing garnish!”

ZYRXOG (Mind Flayer Arcanist, CR 11) floats 40 ft. above the pool on levitate. 2× Octopin (Chuul reskin, CR 4) cling to the wall above the entrance, 30 ft. up. Gear: boots of elvenkind, mantle of spell resistance, necklace of fireballs, 2× potion of greater healing.

M14. Zyrxog’s Private Chamber — Desk, two bookshelves (Free City and undercity lore), locked chest (key on Zyrxog). His open ledger, in Undercommon, logs his recent business in rare and dangerous items — most importantly a sale of “Apostolic Scrolls” to Loris Raknian, director of the Free City Arena, plus a separate payment from Raknian to assassinate the PCs. (Raknian’s motivations and the Apostolic Scrolls are covered in Champion’s Belt, Adventure Path #5.) Chest treasure (DC 30 Thieves’ Tools): 950 cp, 220 sp, 300 gp, 25 pp, and loose gemstones worth 1,500 gp.

Octopin conversion note: Octopins are Zyrxog’s custom terrestrial mollusks, unique to this adventure. Use Chuul as the base (aberration type, tentacle attacks, Constrict), but replace the paralyzing tentacles with Slowing Gaze (DC 15 Constitution save; on a fail, speed halved and -2 to attack rolls until the end of the next turn). Keep everything else from the Chuul stat block. Rename “Chuul” to “Octopin” on your prep.

Monster Roster

3e Monster	Location	5e Conversion	CR	Source	Notes
Human Rogues (Argen/Sald)	Scene 2	Spy × 2	1	MM 349	Increase to Assassin CR 8 if party is strong
Chimera (blue dragon head)	Scene 2	Chimera	6	MM 39	Breath reskinned to 30-ft line, 10d8 lightning, DC 15 Dexterity save; wings clipped
Elaxan	Scene 7	Doppelganger Assassin (MME)	9	MME 77
Tavern Patrons × 14	Scene 7	Thug × 14	0	MM 345	Hostile mob; knives/bottles/chairs as improvised weapons
Mimic × 3	D2	Mimic × 2, Greater Mimic × 1	2	MM 220, MME 189
Martal & Regim	D6	Doppelganger Dark Whisperer × 2	6	MME 78
Invisible Stalker × 2	D7	Invisible Stalker × 2	6	MM 192	Password “deception” bypasses them
Giant Squid	D9	Giant Squid	6	MM 326
Doppelganger × 6 (bedrooms)	D11	Doppelganger	3	MM 82
Doppelganger Guards × 3	D16	Doppelganger Guard	6	MME 77	Boosted; potions of invisibility
Ixiaxian	D15	Doppelganger Assassin	9	MME 77
Telakin (Greater Doppelganger)	D17	Archmage → Berserker	varies	MM 82 base	Transforms at 0 HP
Drow Thralls × 2	D9	Drow Elite Warrior × 2	5	Adventures in Faerûn 260	Fight to the death for Zyrxog
Shrieker × 4	ML1	Shrieker × 4	0	MM 138	Alarm for the entire cave complex
Drow Thralls × 3	M2	Drow Elite Warrior × 3	5	Adventures in Faerûn 260	Oil + alchemist’s fire ambush if warned
Fassash (Spirit Naga)	M3	Spirit Naga	8	MM 234	Neutral; buyable for 1,000 gp tribute
Myrianaas (Drow Cleric 8)	M4	Drow Priestess of Lolth	8	MotM 101
Drow Thralls × 5	M4	Drow Elite Warrior × 5	5	Adventures in Faerûn 260
Zombie × 4	M5	Zombie × 4	1/4	MM 316	Stop escapes, not entries
Octopin × 3	M7	Chuul (reskin) × 3	4	MM 40	See conversion note above
Advanced Octopin	M9	Giant Chuul (boosted)	~10	MM 40	136 HP; Slowing Gaze DC 18 Constitution save or speed halved and -2 attacks; immune to lightning
Vrock	M11	Vrock	6	MM 64	Bound as statue; released if cases disturbed
Zyrxog	M13	Mind Flayer Arcanist	11	Mordenkainen’s Tome of Foes 182
Octopins × 2 (with Zyrxog)	M13	Chuul × 2	4	MM 40	See conversion note above

Treasure Roster

Item	Rarity	Location
Periapt of Health	Uncommon	D5
Bag of Holding	Uncommon	D5
Figurine of Wondrous Power — Onyx Dog	Rare	D7
Frost Brand Greatsword	Very Rare	D17
Scroll of Dominate Person	Rare	D18
Eversmoking Bottle	Uncommon	M3
Fiendish Figurine of Wondrous Power — Bronze Griffon	Rare	M11
Boots of Elvenkind	Uncommon	M13
Mantle of Spell Resistance	Rare	M13
Necklace of Fireballs	Rare	M13

Connections Forward

After the lair, the party should have Zyrxog’s ledger — naming Loris Raknian, director of the Free City Arena, as the buyer of the Apostolic Scrolls and the one who paid to have the party assassinated. That’s the direct hook into Champion’s Belt (Adventure Path #5), where Raknian and the Apostolic Scrolls take center stage.