From the publishers blurb:
Last month, a fleet of holy warships sailed out to destroy the evil sorcerers of the Obsidian Keep.
The fleet never returned.
Today there is a call for righteous heroes (or brave treasure hunters) to find the fleet, rescue the sailors, recover lost treasures, and discover the fate of the cruel masters of the Obsidian Keep!
ADVENTURE TYPE: Exploration / Mystery / Dungeon Delve / Low Level
This adventure is intended for low-level characters (1-3). It is primarily geared for exploration, social encounters, and general mystery-solving. Opportunities for combat lurk everywhere.
It runs 8 to 16 hours.
Players will explore the harbor full of wrecked ships, the beach shanty-town of refugees, the ruined castle grounds, and the Obsidian Keep itself.
There are numerous NPCs as well as unique magical items and other treasures.
NOTE: This adventure was written first for 5e and then converted into an OSR version. In the OSR version, you will find (a very few) 5e-isms and artifacts.
INCLUDES: DM notes, room descriptions, NPC notes, dialogue prompts, stat blocks, original creatures and treasures, and maps.
KEYWORDS: ship, shipwreck, sailor, skeleton, shark, crab, relic, artifact, angelfire, harbor, beach, mystery, lore, grave, rescue, castle, ruin, mutant, horror, mutation, cult, cultist, aberration, negotiation