When I finally found myself adrift and free, I had but little idea of my surroundings. Never a competent navigator, I could only guess vaguely by the sun and stars that I was somewhat south of the equator. Of the longitude I knew nothing, and no island or coast-line was in sight. The weather kept fair, and for uncounted days I drifted aimlessly beneath the scorching sun; waiting either for some passing ship, or to be cast on the shores of some habitable land. But neither ship nor land appeared, and I began to despair in my solitude upon the heaving vastnesses of unbroken blue.

The change happened whilst I slept. Its details I shall never know; for my slumber, though troubled and dream-infested, was continuous. When at last I awaked, it was to discover myself half sucked into a slimy expanse of hellish black mire which extended about me in monotonous undulations as far as I could see, and in which my boat lay grounded some distance away.

SUN AND STARS: Lovecraft’s love of astronomy dates as far back as his twelfth year. For much of his childhood, he planned on becoming an astronomer, but unfortunately, he learned in high school that he simply could not master the advanced mathematics required in modern astronomy. The realization was a bitter one:

The whole thing disappointed me bitterly, for I was then intending to purse astronomy as a career, and of course advanced astronomy is simply a mass of mathematics. That was the first major setback I ever received—the first time I was ever brought up short against a consciousness of my own limitations. It was clear to me that I hadn’t brains enough to be an astronomer—and that was a pill I couldn’t swallow with equanimity.

Not surprisingly, stars, constellations, and other celestial phenomena appear frequently in Lovecraft’s fiction. In “Polaris” (1918), for example, the Pole Star, “leering like a fiend and tempter,” lulls the narrator to sleep, thus preventing him from sounding the alarm when invaders “steal up the pass behind the peak Noton and take the citadel by surprise.”

SOUTH OF THE EQUATOR: Elsewhere the narrator states that his ship was sailing in “one of the most open and least frequented parts of the broad Pacific” when it was attacked. If both statements are accurate, the narrator is, at this point in the tale, probably somewhere north or northwest of French Polynesia.

DREAMS: Lovecraft hints that the narrator, while adrift at sea, may have dreamt the entire episode. By providing an alternative explanation for the story’s supernatural events, Lovecraft adds an additional layer of complexity to the narrative. In a categorical sense, the story belongs to the “ambiguous supernatural,” a subgenre within supernatural horror. “The Tomb” (1917), which Lovecraft finished just before starting “Dagon,” follows the same pattern. Though the narrator insists that he entered the Hyde family’s tomb, everyone else insists that he merely slept outside of it:

What I have dared relate of my experiences within the vault has brought me only pitying smiles. My father, who visits me frequently, declares that at no time did I pass the chained portal, and swears that the rusted padlock had not been touched for fifty years when he examined it. He even says that all the village knew of my journeys to the tomb, and that I was often watched as I slept in the bower outside the grim facade, my half-open eyes fixed on the crevice that leads to the interior.

Like the narrator of “Dagon,” he may have dreamt the entire narrative.

BLACK MIRE: Lovecraft delights in limning certain images, and a sticky, tar-like ooze is one of them. By the end of “Cool Air” (1926), all that remains of Dr. Muñoz is “a kind of dark, slimy trail” which leads “from the open bathroom door to the hall door, and thence to the desk, where a terrible little pool had accumulated.” Similarly, one of the central characters of  “The Thing on the Doorstep” (1933) is, by the end of that tale, reduced to no more than a “liquescent horror.”