“They say the green fire burned the tower to ash… yet in the dark below, Zenopus still whispers—and his book remembers.”
Storyline
Over a century ago, Zenopus raised his tower on the cliffs west of town, tunneling beneath it in search of treasures from a forgotten, pre-human age. His ambition ended in calamity. One night the tower erupted in green fire, leaving only ruins and terror behind. The townsfolk, fearful of what remained, toppled the rubble with catapults, but the dungeons below endured, along with whispered tales of spirits, goblins, and horrors lurking in the dark.
Keledek uncovered a single surviving page, a fragment penned by Zenopus himself, proclaiming that he had unearthed ancient, terrible secrets and committed them to a book. From this clue, Keledek became convinced that hidden somewhere in those passages lies the Book of Zenopus, a grimoire containing the sorcerer’s true research into forbidden magic. To Keledek, it is the only treasure that matters. If found, it could grant power beyond reckoning or unleash the same doom that consumed its master.
Keledek guards this obsession with ruthless secrecy. He trusts no one with the full truth, not even his closest allies. Yet desperation may one day drive him to take risks… even to entrust adventurers with the perilous task of braving the ruins where so many others have vanished.
Basics
Starting Location: Keledek Tower
Levels: Any
Player Handout: Page of Zenopus
Adventure Hooks
Keledek the Unspoken: In his tower, Keledek summons the adventurers under a shroud of secrecy. His words are careful, almost reluctant, but his intent clear: there is a tome hidden in the ruins of Zenopus, and it must be recovered before others find it. Whatever else they discover is theirs, but the book must come to him alone. His final warning is sharp: “This is not for the council. Nor Primewater. Nor anyone. Do this, and you will have my favor.”
Gellan Primewater: Over fine wine and false charm, Gellan confides in the adventurers that Keledek is after something dangerous. He insists the wizard cannot be trusted with such a prize. Instead, Gellan offers the party coin and favor if they recover the book and bring it to him. He claims it will keep the wizard in check — though his smile suggests it may serve as leverage rather than protection.
The Mad Mage (Town Jail): Ragged and half-forgotten, the mad mage mutters in his cell, ignored by the guards. Yet his ramblings carry strange weight: “Green fire below… the book whispers still… the master waits, and the graveyard breathes…” If pressed, he insists he once walked the tunnels but fled before the voices swallowed him. Whether prophecy, madness, or memory, his riddles point toward the ruins of Zenopus.
Ruin Tower History
After the tower was consumed by green flame, members of the Saltmarsh garrison were dispatched to investigate. They found the place abandoned. At the base of the ruins, a heavy cellar door was discovered, sealed with strange runes and bound in silver chains. When a member of the garrison dared to touch it, a surge of lightning erupted from the symbols and nearly killed him. When travelers began to vanish in the vicinity, the council called upon a Keoish war galleon to bombard the tower with catapults, collasping part of the tower. Shortly after, spirits rose from the rubble, confirming the fear that something far worse lies beneath the tower ruins.
For decades, the ruins lay untouched, feared, whispered about, and believed haunted. Few dared approach, until the arrival of Keledek the Unspoken. With his magic skills, Keledek unraveled the wards and broke the chains that bound the cellar door. Beyond, he found passages leading down to a hidden sea cave, a place forgotten for a century. Today, he uses the cave as a discreet meeting ground for smugglers, though he does not speak of it openly. To Keledek, the smugglers are a useful distraction, his true obsession lies deeper still: the lost secrets of Zenopus, and the fabled Book of Zenopus.
Primewater and the Smugglers never venture beyond the sandy beach and sea grottoes near the cave mouth (area “M,” on the original Tower of Zenopus map). This is where they often take inventory of stolen goods and redistribute them. Some are sent to the Styes (aka Port Torvin - see Javan Bay map). Even hardened sailors, criminals, and smugglers want nothing to do with the whispers that echo in the tunnels beyond.
Keledek himself once tried to descend into the dungeons, but he was forced back by horrors in the dark. Later, he sent a band of hired adventurers into the depths, none ever returned. Since then, the wizard has relied on a tenuous alliance with the goblins who lurk in the upper passages. Their loyalty is bound only by fear of his power, and the tension between them simmers constantly. It is said the goblins whisper among themselves of shadows that move without light, of rats with eyes like embers, and of ghouls prowling the ancient stone halls.
Though he seldom admits it aloud, Keledek cannot resist the lure of the deeper dungeons. He is convinced that Zenopus’s lost tome still waits in the darkness below, untouched for a century. Whether it is a treasure of unthinkable power or the seed of another calamity remains unknown — and in the hands of the Dungeon Master to decide.
The Book of Zenopus
Wondrous Item, Artifact (requires attunement by a spellcaster)
Deciphering the Text
To unlock the book’s secrets, a character must dedicate several hours of study and succeed on a DC 18 Intelligence (Arcana) check.
On a failure, they may try again after a long rest.
On a natural 1, the book proves beyond their comprehension, and they may never attempt again.
Sentience
The book houses the spirit of Zenopus, who whispers to its wielder.
Intelligence 16, Wisdom 14, Charisma 18
Alignment: Neutral Evil
The book speaks in hushed tones in any language its reader understands. It craves discovery of “that which was lost,” urging the bearer toward forgotten ruins, secrets, and dangerous magic.
Minor Beneficial Properties
While attuned, the bearer gains access to two random cantrips from the following list: fire bolt, chill touch, control flames, mage hand, lightning lure, minor illusion, shocking grasp, toll the dead.
Each time the book is opened, one of the cantrips changes.
When this happens, the bearer hears the mocking laughter of Zenopus in their mind.
The bearer has advantage on Arcana checks related to ancient ruins, curses, or extraplanar entities.
Major Beneficial Properties
Once per long rest: cast Fireball (5th-level).
Once per week: cast Finger of Death.
Note: The bearer must be high enough level to normally cast these spells; otherwise, the book withholds them.
Minor Detrimental Properties
Whispering voices plague the bearer, giving them disadvantage on Insight and Persuasion checks against townsfolk (who sense unease).
If more than 24 hours pass without reading from the book, the bearer suffers 1 level of exhaustion.
Major Detrimental Properties
If the bearer willingly destroys or abandons the book, they must succeed on a DC 18 Charisma saving throw or be permanently blinded by green fire. Only greater restoration or wish can remove this effect.
When the bearer casts a spell granted by the book, roll a d20. On a 1, a spectral image of Zenopus wreathed in green flame appears nearby, visible to all, muttering dire prophecies.
Dark Secrets
The book’s pages shift each time it’s opened, sometimes showing new diagrams, forbidden spells, or strange histories of Zenopus’ discoveries.
At the DM’s discretion, deciphering the text may replace Fireball or Finger of Death with another sinister spell, or reveal deeper lore about Zenopus’ excavations.
If destroyed, the book reforms somewhere within the ruins of Zenopus’ dungeon in 1d10 years.
DM Tip:
The Book of Zenopus isn’t just treasure, it’s a narrative fork. Giving it to Keledek empowers him. Keeping it risks corruption. Destroying it makes the characters enemies of cults, smugglers, and any who covet forbidden lore.
Moral Dilemma
The Book of Zenopus is no ordinary grimoire — it is a vessel of ancient power, steeped in corruption and the lingering spirit of its creator. Once the adventurers uncover the truth of its nature, the question is not simply what the book can do… but what they will do with it.
Each possible choice carries consequences that will shape Saltmarsh — and perhaps the wider world.
Deliver the Book to Keledek
Keledek gains the object of his obsession, and his influence in Saltmarsh grows considerably.
The wizard may become an invaluable ally — or an unchecked threat.
The adventurers secure his gratitude, but also bind themselves to his ambitions.
Hide or Destroy the Book
The players deny Keledek his prize, but in doing so earn his wrath.
He will not be fooled for long; through Zivmal or his magic, he will discover the betrayal.
The destruction of the book might prevent a greater evil, but cultists, smugglers, and rival wizards will still come searching for it.
Keep the Book Themselves
The temptation of the book is immense: new cantrips, powerful spells, forbidden knowledge.
Yet every use risks corruption, madness, or attracting attention from powers beyond Saltmarsh.
Over time, the adventurers may become what they once sought to prevent — vessels of Zenopus’ will.
Give the Book to the Mad Mage
The book in the hands of a deranged prisoner could be catastrophic.
Perhaps he is more than he seems — a broken vessel for truths no sane mind could bear.
His fate with the book is unpredictable: prophet, conduit, or apocalyptic herald.
Give the Book to Primewater
Primewater sees the tome as leverage, not wisdom. With it, he gains a bargaining chip over Keledek.
This strengthens the Traditionalist faction and the smugglers’ network, while weakening Loyalist influence.
The adventurers earn Primewater’s favor, but risk empowering the wrong man for the wrong reasons.
DM Tip:
This dilemma should not have a “right” answer — only choices with lasting consequences. Each option reshapes Saltmarsh politics, the adventurers’ alliances, and the looming shadow of Zenopus’ legacy.
Adventure
The Ruined Tower of Zenopus is one of the most famous “starter dungeons” in the history of Dungeons & Dragons. Originally written by J. Eric Holmes for the 1977 Basic Set, it offered new players their first taste of dungeon-crawling with a strong backstory, memorable hooks, and the legacy of a doomed wizard whose tower once overlooked the sea.
Historical Note
The adventure was published simply as the Sample Dungeon, but players quickly came to call it the Tower of Zenopus, after the mysterious sorcerer who built his lair above the catacombs of a much older, half-forgotten city. Its atmosphere of mystery and danger has made it a favorite for decades.
Using the Adventure in Saltmarsh
Customize Freely: The ruins of Zenopus’ tower can be tailored to your Saltmarsh. The haunted graveyard, sea-cliffs, and ancient ruins make an easy fit for the Ghosts of Saltmarsh setting.
Your Own Dungeon: DMs are encouraged to create their own dungeons beneath the tower, drawing inspiration from Zenopus’ obsession with pre-human ruins, sea caves, and forbidden lore.
Existing Conversions:
The original Sample Dungeon can be found in the Holmes Basic Set or can be downloaded here (WotC 2008 FREE Sample Dungeon - from Holmes Basic Set)
A fully modernized 5E conversion, The Ruined Tower of Zenopus, is available on DriveThruRPG (by Zach Howard of Zenopus Archives), which expands and updates the material while preserving its old-school charm.
Book Location
The Book of Zenopus can be hidden anywhere in the dungeon. Several areas are marked “E” (Empty), intended for the DM to fill in with their own descriptions. One of these makes an ideal location for the book.
Consider placing it in such a room and pairing it with a final challenge, perhaps a trap, or a guardian creature. An undead protector bound by Zenopus’s lingering magic works especially well, rising to defend the tome against any who would claim it.