From the publisher's website:
Designer Jason Carl takes us to an intriguing lighthouse.
This miniadventure can take place in remote areas or near any coastal city in your campaign -- just set it where it will work best for your current needs.
This is a good side trek adventure -- it's easy to insert it into an existing campaign any time the player characters (PCs) are traveling in a coastal region where fishing and shipping are major industries. Alternately, Black Molly can be the central antagonist in a longer story that you devise. Use the following hooks and rumors to draw the PCs into the encounter.
* The PCs are in the village Poisson when they learn that the lighthouse at Old Captain's Rock has suddenly ceased to shine its light. Fearful of what this occurrence may portend, the village holds its breath. Then they receive Black Molly's ransom message, and pandemonium erupts because even by combining their resources the fishing villages cannot hope to meet the hag's demand. The community's elders appeal to the PCs for assistance, offering a small but heartfelt reward for their help.
* Because the lighthouse is vital to the health of shipping (not to mention sailors) in the region, a group of merchants with marine interests raises the ransom. They hire the PCs to deliver it to Black Molly, but offer them a hefty bonus if they can manage to dispatch the sea hag and return home with the ransom intact.
* The PCs hear a local legend that tells of a fabulous treasure lying at the bottom of the sea near the lighthouse. According to this tale, a war galley named the Flying Cloud went to the bottom during a violent storm over a decade ago, taking all hands with it. These stories speak of a great treasure that sank along with its captain, who went down with his ship.
Suitable for four 10th-level characters.