Shiiiiiiiiiing is the sound of something being dragged against something else, deep in the Russian submarine's reactor, and shiiiiiiiiiing against the outside of the ship, and "Vast, Polyphemus-like, and loathsome, it darted like a stupendous monster of nightmares to the monolith, about which it flung its gigantic scaly arms, the while it bowed its hideous head and gave vent to certain measured sounds." at the edge of each individuals ability to hear.