Animal fury and orgiastic licence here whipped themselves to daemoniac heights by howls and squawking ecstasies that tore and reverberated through those nighted woods like pestilential tempests from the gulfs of hell.
Yow! Or how about the subsequent sentence, which tells us (if the first didn't provide enough clues!) what this is:
Now and then the less organised ululation would cease, and from what seemed a well-drilled chorus of hoarse voices would rise in sing-song chant that hideous phrase or ritual: "Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn".
"Sing-song chant", my eye -- sounds more like gargling to me. This choice mouthful comes of course from H. P. Lovecraft, "The Call of Cthulhu." Unfortunately, in this volume (Tales, in a handsome Library of America edition), it comes toward the bottom of page 179. The actual fifth sentence on p. 123 reads:
I scraped further, and saw that it had form.
Disappointing; but that's the point of the game, I guess. Incidentally, this is the climax of "The Shunned House." You can guess what's going on here from sentence eight:
Still more I scraped, and then abruptly I leaped out of the hole and away from the filthy thing; frantically unstopping and tilting the heavy carboys, and precipitating their corrosive contents one after another down that charnel gulf and upon the unthinkable abnormality whose titan elbow I had seen.
Hmm; not grammatical, that one. (carboy, n. [Per. qaraba, a large bottle.] a large bottle of green glass, enclosed in basketwork or securely boxed for protection: used especially for carrying corrosive liquids, as sulfuric acid.) Come to think of it, sentence five is growing on me -- in a way it's actually creepier, when taken out of context like that.