<p>The Shadow over Innsmouth is great a horror novella by H. P. Lovecraft written in 1931 which forms part of the Cthulhu Mythos using its motif of a malign undersea civilization. It also makes references to several shared elements of the Mythos including place names mythical creatures and invocations.</p><p>The narrator who is a student on an antiquarian tour of New England&nbsp;sees a piece of exotic jewelry in a museum and learns that its source is the nearby decrepit seaport of Innsmouth. Then he travels to Innsmouth and observes disturbing events and people.</p><p>This is the only Lovecraft story which was published in book form during his lifetime.</p>