As a little promise, here's the intro to "Black Cod Island" my particular piece of the horror that is DG:TOO. 

In 1928, a Federal raid on the quiet Massachusetts fishing town of Innsmouth revealed previously unknown depths of horror to a select few in the American government. Innsmouth made clear that all human science had wrought in twenty shallow centuries meant nothing in the face of the inhuman energies from beyond. This secret hovered at the periphery of organized government, too horrible to fit into the limited world-view of the time. It was too unwieldy to manage. For years it existed only in files, bland photographs of impossible creatures and matter-of-fact Marine Corps reports of the “Innsmouth Uprising”. It sunk like a stone to the basements and files of various agencies, covered up; forgotten — as best as such things could be.

At the time mankind was covering the globe in ever expanding networks of information. The few remaining blank edges of the world map were slowly being drawn in. No one was interested in an anomaly that could not be explained by rational minds, they wanted Newtonian science and carefully catalogued species, not the non-euclidian madness that is the Mythos.

With Innsmouth crushed, it would be more than a decade before attention was drawn back to the mysteries presented there. When Delta Green was given official sanction in 1943 as a department of the Office of Strategic Services, and the war against the unknown truly began, America was considered, by those very select few in the know, to be clear of such tainted communities.

Innsmouth, they were certain, represented the darkest heart of infection these other-worldly creatures had wrought in our country. 

Now, with the town a smoking ruin, its only survivors held in medical custody, a thousand alien trinkets lined up, photographed and stored, and a million leads closed so that it represented a perfect, healed wound, they were certain the worst was over, as far as America went. 

The war against evil would continue elsewhere in the darker regions of the world.

America was clean.

They were wrong.

Innsmouth was not the first infection by any stretch of the imagination. It was not even close. The first settlement to hold congress with the creatures from beneath the ocean humans call the Deep Ones summoned the creatures from the sea nearly one hundred years before Columbus landed on the continent.

This community still exists today, though it has moved several times in its long, long existence. It finally settled, one-hundred and sixty years ago on a small island, twenty-six miles southwest of Ketchikan, Alaska.

To the locals, they are known as the Black Cod, descendants of the Haida Indians of Queen Charlotte Islands, British Columbia. They are considered a peaceful, insular, quiet community who have not had any outside conflict with others in their recorded history on the island.

Within their ranks, they are known as the children of the Fish-Wife. 

To the other, untainted people of the Haida Indian culture, they are known as Devil-Fish People.