”Haita the Shepherd” / A Cthulhu Mythos Story by Ambrose Bierce

From Bierce's "Can Such Things Be?" collection. Haita is a naive shepherd who prays at the shrine of Hastur, god of shepherds, and knows nothing of his origin. When great storms threaten to drown the cities of the valleys, he threatens to abandon his worship, blackmailing Hastur into saving them by transforming the water into the sea. He cares for a holy hermit living an hour away and he enlightens him as to the identity of the maiden he has met.