在香港這座城市的地下世界裡，地鐵如同一條永不停歇的脈絡，日夜穿梭於城市的每個角落。無數人依賴著這個系統，卻很少有人真正留意那些隧道深處的黑暗。地鐵的第三條軌道，帶著高壓電流，為列車提供動力，但在都市傳說中，它卻被賦予了另一層詭異的意涵。
許多地鐵員工都說，夜深人靜時，隧道裡的氣氛總是異常壓抑。阿輝是一名地鐵維修工，已有十多年的工作經驗。他知道這些傳說，但從未真正放在心上。然而，那個夜晚改變了一切。那天晚上，阿輝和幾個同事在某條地鐵路線上進行例行維修。隧道內只有他們的頭燈微弱地照亮著周圍，空氣中瀰漫著潮濕的金屬氣味。隨著列車停駛，整個隧道陷入一片寂靜，只剩下工具的敲擊聲偶爾打破沉默。
阿輝沿著軌道巡查，手裡拿著手電筒。他的目光不時掃過第三條帶電軌道，心中雖然明白這只是普通的供電設施，但還是忍不住感到一絲寒意。突然，他的目光被遠處的一個模糊身影吸引住了。那是一個人影，站在月台邊緣，低著頭，好像在注視著什麼。阿輝心頭一震，立刻向那邊走去。他以為是有人誤入了隧道區域，心想得趕緊提醒對方離開。
然而，當他走近時，那個人影卻突然消失了。阿輝愣住了，他環顧四周，但除了空蕩蕩的月台和軌道，什麼也沒有。他心裡泛起一股莫名的不安，但還是強迫自己鎮定下來，繼續完成巡查工作。然而，那個夜晚並沒有就此結束。
就在阿輝準備回到同事身邊時，他突然聽到一陣低沉的腳步聲，從隧道深處傳來。那聲音很輕，但在寂靜的環境下顯得格外清晰。他轉過身，用手電筒照向聲音的來源，但什麼也沒看到。腳步聲卻越來越近。他的心跳加速，手心開始冒汗，但理智告訴他這可能只是回音。他深吸一口氣，大聲喊道：「有人嗎？請不要留在隧道裡，很危險！」
沒有回應。只有腳步聲，仿佛在嘲笑他的膽怯。他再度舉起手電筒，這次終於看到了什麼——那是一雙腳，穿著舊式皮鞋的腳，正慢慢地向他走來。但當他將光線移上去時，那雙腳上方卻什麼都沒有，就像是懸浮在半空中一般。
阿輝嚇得倒退了幾步，不小心踩到了第三條帶電軌道旁的一塊碎石，差點摔倒。他喘著粗氣，不敢再看那方向，只能閉上眼睛，不停地念著：「這不是真的，只是我看錯了而已。」當他再次睜開眼睛時，那雙腳已經不見了。但他知道，那不是他的錯覺。
隔天，阿輝將這件事告訴了幾個同事。原本以為會被嘲笑，但沒想到其中一位年長的工友老張卻面色凝重地說：「你不是第一個看到那些東西的人。」老張低聲講述了他多年前的一次經歷，那是一次深夜清理工作，他也曾看到一個模糊的人影站在第三條軌道旁邊。那人影低著頭，一動不動，就像是在等待什麼。當老張試圖靠近時，那人影卻突然消失，只剩下空蕩蕩的隧道和冷冰冰的鋼軌。
「我後來才知道，那段路曾經出過事故，有個人掉下去觸電身亡。」老張說完後便不再多言，只是拍了拍阿輝的肩膀。「小心點吧，有些東西雖然看不見，但它們可能一直都在。」
從那天起，阿輝對第三條軌道多了一分敬畏。他開始注意到更多細節，比如有時候列車即將進站時，他似乎能看到一個影子站在遠處。但當列車停下後，那影子就消失得無影無蹤。他也曾聽到過低語聲，就像有誰在耳邊說話，但回頭看去，卻什麼也沒有。
有一次，他甚至夢見自己站在月台邊緣，看著第三條軌道，突然感覺有人從背後推了他一把。他驚醒後發現自己滿身冷汗，再也無法入睡。
漸漸地，他開始相信那些都市傳說或許並非全然虛構。在這座城市的地下世界裡，有些故事無法用科學解釋，也許它們只是過去某些悲劇的殘影，也許是人類潛意識中的恐懼投射。但無論如何，每當他獨自站在空蕩蕩的月台上時，總忍不住回頭看看那條帶電的第三軌。
黑暗中似乎有什麼東西在注視著他，而他能做的，只是祈禱那東西永遠不要靠近。
English Version
Beneath the surface of Hong Kong, the underground railway system runs like an endless vein through the city, carrying millions of passengers every day and night, yet while most people rely on it without a second thought, few ever consider the darkness that stretches deep within its tunnels, where the third rail, charged with high-voltage electricity, silently powers each passing train, and in urban legends, this same rail is said to carry something more than energy, something that lingers in the shadows and reveals itself only when the system grows quiet, and among those who know these stories best are the workers who spend their nights maintaining the tracks, people like Ah Fai, a maintenance worker with more than a decade of experience, someone who had heard the rumors many times but had never truly believed them, dismissing them as nothing more than stories passed down to make long nights more interesting, until one particular night changed his perspective entirely, when he and a few colleagues were assigned to carry out routine maintenance along a section of track after service hours, entering the tunnel with only the narrow beams of their headlamps to illuminate their surroundings, the air heavy with the damp metallic scent of steel and electricity, and with the trains no longer running, the silence in the tunnel felt absolute, broken only occasionally by the sound of tools striking against metal, echoing faintly into the distance, and as Ah Fai walked along the track inspecting the line, his flashlight sweeping across the rails, his gaze lingered briefly on the third rail, fully aware of its function yet unable to ignore a subtle unease that seemed to arise whenever he looked at it, and it was during this quiet moment that something caught his attention, a vague figure standing far ahead near the edge of the platform, its outline blurred by distance and darkness, appearing to be a person standing still with their head lowered as if staring down at the track, and instinctively, Ah Fai assumed it was someone who had somehow entered the restricted area, prompting him to move quickly toward the figure with the intention of warning them away, but as he approached, the figure vanished without warning, disappearing so suddenly that it left him momentarily frozen in place, his mind struggling to make sense of what he had just seen, and when he scanned the area again, there was nothing there, no movement, no sign that anyone had ever been present, only the empty platform and the silent tracks stretching into the darkness, and although a sense of unease began to settle in his chest, he forced himself to remain calm and continue his work, telling himself that there must be a logical explanation, yet the night was far from over, because as he turned to head back toward his colleagues, he heard something that made his entire body tense, a low, steady sound of footsteps echoing from deep within the tunnel, faint at first but unmistakable in the silence, and as he turned toward the source of the sound, raising his flashlight to cut through the darkness, he saw nothing, yet the footsteps continued, growing closer with each passing second, causing his heartbeat to quicken and his grip on the flashlight to tighten, and though his rational mind insisted it could be an echo or some natural acoustic effect, the clarity of the sound made it difficult to dismiss, and taking a deep breath, he called out into the tunnel, warning that it was dangerous to remain there, his voice carrying into the distance but receiving no reply, only the persistent approach of those unseen footsteps, and then, as he focused his light more carefully, he finally saw something, not a full figure but a pair of feet emerging from the darkness, wearing what appeared to be old-fashioned leather shoes, moving slowly toward him along the track, and as the beam of light traveled upward in an attempt to reveal the rest of the figure, he realized with growing horror that there was nothing above them, no body, no face, only those disembodied feet advancing step by step as if walking through empty air, and the sight caused him to stumble backward in shock, nearly losing his balance as his foot struck a loose stone near the third rail, his breath becoming rapid and uneven as fear took hold, and unable to bear the sight any longer, he shut his eyes tightly, repeating to himself that it was not real, that he must be mistaken, and when he finally opened his eyes again, the feet were gone, leaving only the silent tunnel once more, yet deep inside he knew that what he had seen was not something easily explained away, and the following day, when he shared the experience with his colleagues, he expected laughter or disbelief, but instead, one of the older workers, known as Lao Cheung, reacted with a seriousness that surprised him, quietly telling him that he was not the first to witness such things, and recounting his own experience from many years before, when he too had seen a figure standing beside the third rail late at night, motionless and silent, only to vanish the moment he tried to approach, leaving behind nothing but the cold steel tracks, and it was only later, Lao Cheung explained, that he learned an accident had once occurred on that very stretch of track, where someone had fallen and been electrocuted by the third rail, a tragedy that seemed to linger in the space long after it had happened, and from that point on, Ah Fai found himself unable to look at the third rail in the same way, becoming more aware of subtle details he had previously ignored, such as the occasional glimpse of a shadow standing in the distance just before a train entered the station, disappearing as soon as the train arrived, or the faint sound of whispering that sometimes seemed to drift past his ear when he stood alone on the platform, only to vanish when he turned to investigate, and on one occasion, he even dreamed that he was standing at the edge of a platform, staring down at the third rail, when he felt a sudden push from behind that sent him falling forward, waking abruptly in a cold sweat, unable to shake the sensation that the dream had felt far too real, and over time, his skepticism began to fade, replaced by a cautious respect for the stories he had once dismissed, because in the hidden world beneath the city, not everything could be explained through logic or science, and perhaps what people call urban legends are not entirely fictional, but fragments of past tragedies, echoes that remain imprinted in certain places, or manifestations of fears that take shape in the darkness, and regardless of their origin, the effect they have is undeniable, and now, whenever Ah Fai finds himself alone on a quiet platform late at night, he cannot help but glance toward the third rail, aware of the darkness that stretches beyond it, and the possibility that something unseen may be watching from within it, something that does not need to reveal itself fully to make its presence known, and in those moments, all he can do is remain still and hope that whatever lingers there will choose to stay where it is, never stepping closer, never crossing the thin boundary that separates the visible world from whatever lies just beyond it.
