The word "sentinel" is deployed with versatile nuance in literature to evoke vigilant watchfulness and the notion of guarding, whether in a literal or metaphorical dimension. Often, it designates a watchman physically patrolling a space—be it a corridor, a gate, or a strategic post—as seen when a character marches like a guardian in a domestic setting ([1]) or when a sentinel stands alert by a bank or door ([2], [3]). At the same time, the term stretches into symbolic territory, representing a watchful presence in nature or in the human spirit; for instance, it transforms into a silent, ever-present observer in a forest scene ([4]), or becomes the metaphorical keeper at the threshold between life and death ([5]). Its recurrent use across narratives—from courtrooms and castle gates to metaphoric landscapes steeped in foreboding or protection—illustrates how authors harness the image of the sentinel to imbue their settings with an air of steadfast vigilance and, occasionally, ominous isolation ([6], [7], [8]).