In literature, “subterranean” is a multifaceted term that oscillates between the literal and the metaphorical. Authors employ it to evoke images of hidden, often mysterious spaces—underground passages [1], secret chambers [2], and vast, unexplored networks [3]—which serve as portals to adventure or dread, as seen in Jules Verne’s vivid descriptions of underground seas and tunnels [4], [5], [6]. At the same time, writers like Nietzsche and Chesterton use “subterranean” figuratively to suggest underlying forces in society or the human psyche, as in secret conspiracies or repressed passions [7], [8]. Whether highlighting the physical realm beneath our feet [9], [10] or symbolizing the dark, concealed undercurrents of truth and power [11], [12], the word enriches literary narratives by conjuring an atmosphere of enigmatic, often ominous depth that continues to intrigue readers across genres [13], [14].