Innsmouth’s Secrets Uncovered

Innsmouth is the definitive guide to the rotting seaport town—one of the most iconic settings for Call of Cthulhu.

Once a thriving seaport on the Massachusetts coast during the 19th century, a dark shadow has fallen over Innsmouth—Some say old Captain Obed Marsh made a pact with the Devil, while others tell stranger and more wicked tales.

What's Inside?

In the early 1920s, the town’s former glories are long forgotten, and wise folk keep away. Secrets have a currency in Innsmouth, and the unwary pay a high price for asking the wrong questions.

A Sandbox Campaign Setting

An essential resource for Innsmouth-based scenarios as well as campaigns within the wider Arkham and Miskatonic Valley region. Description, insights, and plot seeds from over 100 Innsmouth locations in and around the town.

Secrets to Uncover

Call of Cthulhu: Innsmouth includes street maps in player and Keeper versions, as well as floorplans for key locations, gossip and rumors to spark further mysteries and adventure. The book also covers the secrets, intrigues, and profiles for more than 80 characters and encounters.

The Dreaded Order of Dagon

The book details the full secret history of Innsmouth, its unseen masters, and specifics about the mysterious Esoteric Order of Dagon. You’ll also find extensive information about the Dagon cult, and the horrid Deep Ones—with entirely new and horrifying aspects.

For Mature Readers: contains mature themes and is intended for mature players.

This supplement is part of the Arkham Unveiled line and is designed for use with both the Call of Cthulhu roleplaying game and, optionally, the Pulp Cthulhu supplement, both available separately.

It may not be possible to ship very heavy items outside of the Mainland UK.
Released: 04 August 2026