What Is the Cthulhu Mythos?
Beneath recorded history lie the Great Old Ones — entities of incomprehensible power who are not dead but dreaming. In this campaign the Mythos is not religion or myth — it is fact hidden behind the veneer of history. The Great Old Ones are real. This is not a campaign about heroes defeating evil. It is about people who discover the truth about reality — and choose, in spite of that truth, to resist.
The Stars Are Right
Once per millennium, a celestial phenomenon called The Alignment creates resonance between the physical world and the prison-dimensions where the Great Old Ones slumber. The current alignment is in progress — it began three weeks before the campaign opens. The party has roughly four weeks before the window closes.
The Sea Awakens
As the alignment deepens, the influence of sleeping Mythos entities bleeds into the physical world through the ocean. Strange weather, unprecedented whirlpools, ship disappearances, and bizarre sea creature behavior are the first signs. The entity known as The Dreaming Thing — a manifestation of Cthulhu — stirs in its deep-ocean prison.
Campaign Overview
| Act | Title | Levels | Summary |
|---|---|---|---|
| Act I | "The Stars Are Right" | 1–5 | The players are drawn into the conspiracy aboard the Unsinkable III. They survive a catastrophic storm, protect two mysterious children called Resonants, and wash ashore on a fog-shrouded island that should not exist. |
| Act II | "Waterdeep Underbelly" | 5–9 | Rescued and brought to Waterdeep, the party discovers the Cult of the Drowned God has deep roots in the city — among merchants, city officials, and the city guard. |
| Act III | "The Ritual Site" | 9–15 | The trail leads to a remote volcanic island where the summoning will take place. The party must reach it and confront the High Apostle before the alignment window closes. |
Factions
The Cult of the Drowned God
Fanatical worshippers of Cthulhu who believe the Resonant children are ritual keys. They operate in secret across port cities, embedded in merchant guilds, shipping companies, and dockworker unions.
The Wardens of the Veil
A secret society of investigators, scholars, and warriors. Criella, the tiefling ranger, is a senior Warden. Most long-serving Wardens carry multiple Dreadful Insights.
The Sapphire Mystic
A neutral magical order based in Waterdeep. They possess texts crucial to understanding the ritual. Whether they become allies or obstacles depends on how the party approaches them.
Key Locations
1. The "Unsinkable III"
A three-masted merchant vessel ~200 feet long. Decks: Main Deck (rigging), Galley/Dining Level, Below-Deck Passenger Quarters, Cargo Hold, Captain's Quarters.
2. The Open Sea
Three to four days from Waterdeep. The horizon featureless, vast, humbling. 4,000 feet deep beneath the hull.
3. The Dreaming Stone (Remote Island)
A volcanic, fog-shrouded island ~300 miles from any charted landmass. Dense jungle, wrong sounds. Ancient stone structures at its center carved with elder signs.