The Shadow over Innsmouth

Blurb

The Shadow over Innsmouth is a horror novella by H. P. Lovecraft, written in November–December 1931. It forms part of the Cthulhu Mythos, using its motif of a malign undersea civilization. It references several shared elements of the Mythos, including place-names, mythical creatures and invocations.
The narrator is a student on an antiquarian tour of New England. He sees a piece of exotic jewelry in a museum, and learns that its source is the nearby decrepit seaport of Innsmouth. He travels to Innsmouth and observes disturbing events and people. A local resident tells him a horrifying story of aquatic monsters who can interbreed with humans to produce amphibian hybrids. The student is tricked into staying overnight in the town, and he is attacked in his hotel. He flees, but finds that his pursuers are the hybrid monsters of his informant’s story. He alerts the authorities, who take drastic action. He then discovers that he has alien ancestors and must eventually return to the sea.
It is the only Lovecraft story which was published in book form during his lifetime.