Desolate and abandoned, the evil alchemist's mansion stands alone on the cliff, looking out towards the sea. Mysterious lights and ghostly hauntings have kept away the people of Saltmarsh, despite rumors of a fabulous forgotten treasure. What is its sinister secret?

The first in the "U"nderwater series of modules, set in and around Saltmarsh in the World of Greyhawk.

For characters levels 1-3.