Shadow over Innsmouth

A young antiquarian, intrigued by an unusual piece of jewelry in a museum, travels to the decrepit New England seaport of Innsmouth to learn its origin. There, an old drunk named Zadok Allen tells him of Obed Marsh, a merchant who once struck a bargain with an amphibious race called the Deep Ones — human sacrifices and interbreeding in exchange for wealth — founding the town's secretive Esoteric Order of Dagon.

Trapped overnight in Innsmouth, the narrator is hunted through its empty streets by the town's fish-human hybrid inhabitants, barely escaping — only to later discover his own ancestry traces back to the very bloodline that brought the horror to Innsmouth in the first place. H.P. Lovecraft's 1936 novella remains one of his most influential works, cementing the Deep Ones and the Esoteric Order of Dagon as cornerstones of Cthulhu Mythos fiction.