The investigation ultimately concluded with the arrest and detention of many of the town's residents in concentration camps as well as a submarine torpedoing nearby Devil Reef, which the press falsely reported as Prohibition liquor raids.

The narrator proceeds to describe in detail the events surrounding his initial interest in the town, which lies along the route of his tour from Ohio across New England, taken when he was a 21-year-old student at Oberlin College.

A local merchant named Obed Marsh built a profitable gold refinery, but the town only deteriorated further after riots and after a mysterious epidemic eliminated half of its residents in 1845.

He finds Innsmouth to be a mostly deserted fishing town full of dilapidated buildings and people who walk with a distinctive shambling gait and who have "queer narrow heads with flat noses and bulgy, stary eyes."

After exploring the town to find unusual architecture and an area of fisherman who exhibit advanced symptoms of the odd Innsmouth degradation, the narrator happens upon the fully human Zadok.

While trading in the Caroline Islands Obed Marsh discovered a Kanak tribe in Pohnpei who offered human sacrifices to a race of immortal fish-like humanoids known as the Deep Ones.

When hard times fell on Innsmouth, Marsh's cult performed similar sacrifices to the Deep Ones in exchange for wealth in the form of large fish hauls and unique jewelry.

Male and female inhabitants were forced to breed with the Deep Ones, producing hybrids who upon maturing permanently migrate underwater to live in the city of Y'ha-nthlei, located underneath Devil Reef.

After reaching Arkham and alerting government authorities about Innsmouth, the narrator discovers that his grandmother was related to Obed Marsh's family, although the origins of her mother were unclear.

His story starts to use odd words and phrases with seemingly no awareness of doing so, his previous convictions lessen, and he begins having dreams of his grandmother and Pth'thya-l'yi in Y'ha-nthlei, which was damaged but not destroyed by the submarine attack.

This is a central tenet of Cosmicism, which Lovecraft emphasizes in the opening sentence of "The Call of Cthulhu": "The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents.

"[10] "Fishhead" is the story of a "human monstrosity" with an uncanny resemblance to a fish: his skull sloped back so abruptly that he could hardly be said to have a forehead at all; his chin slanted off right into nothing.

[11] Lovecraft, in "Supernatural Horror in Literature," called Cobb's story "banefully effective in its portrayal of unnatural affinities between a hybrid idiot and the strange fish of an isolated lake".

Wells' short story "In the Abyss" (1896):[15] Two large and protruding eyes projected from sockets in chameleon fashion, and it had a broad reptilian mouth with horny lips beneath its little nostrils.

The project came to fruition in November 1936 (although the copyright page declares the date of publication as April 1936), but the book had so many typographical errors that Lovecraft insisted on an errata sheet (which was also faulty).

Lovecraft was displeased with the production; writing to his correspondent Lee McBride White on Nov 30, 1936, he wrote: "My Shadow over Innsmouth is now out - but as a first cloth-bound book it doesn't awake any enthusiasm in me.

The solitary redeeming feature is the set of Utpatel illustrations - one of which, on the dust wrapper, saves the appearance of the thing..."[18] It had a bound run of 200 copies — the only book of Lovecraft's fiction distributed during his lifetime.

[22] As L Sprague de Camp noted, the action sections of Innsmouth are a departure for Lovecraft; the story's tense and memorable siege scene within the titular town's hotel reveals a flair in execution on a par with some of the most compelling chapters of R L Stevenson's Kidnapped.

The collection was edited by Stephen Jones, and included contributions by Neil Gaiman, Ramsey Campbell, David Sutton, Kim Newman (both as himself and Jack Yeovil), and other authors.