The first chapter, "The Horror in Clay", concerns a small bas-relief sculpture found among the notes, which the narrator describes: "My somewhat extravagant imagination yielded simultaneous pictures of an octopus, a dragon, and a human caricature. ... A pulpy, tentacled head surmounted a grotesque and scaly body with rudimentary wings.” The sculpture is the work of Henry Anthony Wilcox, a student at the Rhode Island School of Design, who based his creation on a delirious dream of "great Cyclopean cities of titanic blocks and sky-flung monoliths, all dripping with green ooze and sinister with latent horror.” References to both Cthulhu and R'lyeh are included in letters written by Wilcox.