Eons and unimaginable eons ago, before mankind existed on earth, only the waters existed. There was no land. And from the slime there sprang up a race of beings which dwelt in the sunken abysses of the ocean, inhuman creatures that worshipped Dagon, their god. When eventually the waters receded and great continents arose, these beings were driven down to the lowest depths. Their mighty kingdom, that had once stretched from pole to pole, was shrunken as the huge land masses lifted. Mankind came — but from whence I do not know — and civilizations arose. … These things hate man, for they feel that man has usurped their kingdom. Their greatest hope is to sink the continents again, so that the seas will roll over all the earth, and not a human being will survive. Their power will embrace the whole world, as it once did eons ago. They are not human, you see, and they worship Dagon. They want no other gods worshipped on Earth. Ishtar, dark Eblis, even Poseidon of the sunlit seas. . . .
Henry Kuttner