清晨的大潭水塘，一片寂靜，霧氣籠罩著整個山谷，彷彿將時間凍結在那一刻。水塘的水面平靜如鏡，偶爾有微風掠過，帶動一絲絲波紋，卻很快又歸於平靜。我習慣在這樣的早晨出門行山，享受那份清涼與寧靜。然而那一天，霧比平常更濃，更重，彷彿整個世界都被吞噬，只剩下眼前的一小片空間。
我沿著山路走著，耳邊傳來水塘溢流的聲音，低沉而持續。走了幾分鐘，霧裡逐漸浮現了一座橋，那是一座古老的石橋，橋欄漆成白色，在霧中顯得格外醒目。我走上橋，四周霧氣繚繞，視線受限，只能看到腳下的石板和身旁模糊的白色欄杆。橋的另一端完全隱沒在霧中，彷彿通往未知的世界。
就在我站在橋中央時，突然聽到腳步聲。那聲音緩慢而沉穩，每一步都像敲擊在我的心上。我抬起頭，試圖看清來者，但霧太濃，只能隱約看到一個模糊的人影。那人影像是個男人，背著背包，步伐緩慢卻穩定。他從橋的另一端走來，沒有看我，只是默默地經過。我站在一旁讓路，看著他逐漸消失在霧中。
當時我並未多想，只以為是另一個早起行山的人。然而當我繼續走上山路時，心中卻生出一絲奇怪的感覺。那座橋並不長，如果那人一直往前走，他應該會出現在我的視線裡。但幾分鐘過去，前面的山路空空如也，只有霧氣環繞。我停下腳步回頭看，那座橋已完全隱沒在霧中，像從未存在過。
這件事雖然奇怪，但我並未深究。直到幾個月後，我在茶餐廳聽到兩個老人聊天。他們提到大潭水塘，其中一人說：「你有冇試過霧天行橋？」另一人笑著回答：「你講白橋？」我聽到這裡不禁留意起來。老人接著說：「有啲人話，霧重嘅時候，橋上會多一個人。」另一人問：「多一個？」老人點頭說：「你上橋時可能只有你一個，但落橋時可能已經唔止。」
這番話讓我心頭一震，我想起那天早上的事。那個從霧中走來的男人，我一直以為他是從橋的另一端上來的。但如果仔細想想，那天的霧如此濃重，我根本看不到橋的另一端，也看不到橋的入口。那個人或許不是從橋那邊走來，也可能……他一直都在橋上，只是我走上去時，橋上本來就不止一個人。
回想起來，那天早晨的腳步聲，那模糊的人影，那消失得無影無蹤的身影，都像是一場迷霧中的幻影。然而每次再經過大潭水塘，我都忍不住想起那座白橋和那個霧中的人影。或許，在某些特定的清晨，霧氣會打開另一扇門，而白橋只是通往那扇門的一部分。至於門後的世界，是什麼樣的存在，我不敢去想，也不願去探尋。
English Version
At dawn, Tai Tam Reservoir rests in an uncanny stillness, as if the entire valley has been gently sealed away from the passage of time, the surface of the water lying flat like polished glass while a pale, shifting mist drapes itself across the hills and trees, softening every outline and swallowing every distant detail until only fragments of the world remain visible, and on mornings like these I often set out alone to hike, drawn by the quiet, the cool air, and the strange comfort of being suspended between clarity and obscurity, yet on that particular day the fog felt heavier than usual, denser, almost deliberate, as though it were not simply a natural occurrence but something that had intention, something that narrowed the world into a confined corridor where only what stood directly before me could exist, and everything else had already been erased, so I followed the familiar path, guided more by memory than sight, listening to the low and constant sound of water spilling from the reservoir, a steady murmur that seemed to echo from everywhere and nowhere at once, until gradually, through the veil of white, a shape began to emerge, first as a faint suggestion, then as a structure with clearer edges, revealing itself to be the old stone bridge, its railings painted white, standing stark and unnatural against the gray mist like a boundary marker between two realms, and without hesitation I stepped onto it, my footsteps dull against the stone surface, the world shrinking even further as the fog thickened around me, limiting my vision to only the immediate ground beneath my feet and the pale railings at my sides, while the far end of the bridge remained completely hidden, not just obscured but seemingly nonexistent, as if the bridge did not lead anywhere at all but instead stretched into an unfinished space, and it was at the midpoint, surrounded by silence and whiteness, that I heard it, the sound of footsteps approaching from ahead, slow, deliberate, each step measured and steady, resonating unnaturally loud in the confined stillness, as though the bridge itself were amplifying the sound, and I instinctively looked up, straining my eyes into the mist, trying to identify the source, and gradually a figure took shape, indistinct at first, then clearer, the outline of a man carrying a backpack, his posture relaxed yet purposeful, his pace unhurried, and though I expected some form of acknowledgment, a glance, a nod, any sign of awareness, he offered none, simply continuing forward as if I were invisible, so I stepped aside to let him pass, watching as he moved past me and into the fog behind, his form dissolving piece by piece until there was nothing left but the lingering echo of his footsteps, and at that moment nothing seemed particularly unusual, it was easy to assume he was just another early hiker, someone who, like me, had chosen to embrace the solitude of the morning, yet as I continued off the bridge and followed the path upward, a subtle unease began to form, a quiet but persistent thought that something did not align, because the bridge was not long, not nearly long enough for someone walking at that pace to vanish entirely within a matter of seconds, and if he had continued along the same trail, I should have seen him ahead, even through the fog, at least a shadow, a movement, some indication of his presence, but there was nothing, only the empty path stretching forward, wrapped in silence, and when I finally stopped and turned back, the bridge itself had disappeared, completely swallowed by the mist as though it had never existed at all, leaving me standing alone in a landscape that felt subtly altered, and although the experience lingered in my mind, I did not dwell on it, dismissing it as a trick of perception, an effect of the heavy fog playing with distance and visibility, until months later, when I happened to overhear a conversation in a small local café, two elderly men speaking casually about hiking routes, their voices low but clear enough to catch fragments of their exchange, and one of them mentioned Tai Tam Reservoir, asking the other if he had ever crossed the bridge in heavy fog, to which the second man responded with a knowing smile, referring to the white bridge specifically, and it was then that my attention sharpened, drawn fully into their conversation as the first man continued, explaining in a matter-of-fact tone that some people believed that on particularly misty days, there would always be one extra person on the bridge, a statement that seemed almost absurd at first, yet carried an unsettling weight in its simplicity, prompting the other man to ask what he meant by “one extra,” and the reply came without hesitation, that when you step onto the bridge, you might think you are alone, but by the time you step off, there may be more people than when you started, and hearing this, I felt a chill that had nothing to do with the air, because in that instant the memory of that morning returned with sharp clarity, the sound of those footsteps, the silent figure passing by, the impossible disappearance, and I began to reconsider what I had seen, or rather, what I had assumed I had seen, because I had believed that the man approached from the opposite end of the bridge, that he must have entered from the far side and walked toward me, but in truth, I had never seen the entrance to the bridge, nor had I seen its far end, both were completely concealed by the fog, meaning there was no definitive proof of where he had come from, and a far more unsettling possibility emerged, that perhaps he had not entered the bridge at all, that perhaps he had been there the entire time, already present before I stepped onto it, hidden within the mist, waiting or simply existing in that space, unnoticed until the moment our paths intersected, and the idea lingered, reshaping the memory into something far more ambiguous, because if that were the case, then the bridge was not merely a physical structure but a place where perception could not be trusted, where the boundaries between presence and absence blurred, and since that day, every time I pass by Tai Tam Reservoir, I find myself thinking of that white bridge, of the figure in the fog, of the quiet suggestion that under certain conditions, reality itself may shift just enough to allow something else to overlap with our world, something that does not announce itself, does not interact in any meaningful way, but simply passes through, leaving behind only a question, and perhaps that is what unsettles me most, not the idea that I encountered something unknown, but the possibility that I did not notice it fully, that I accepted it as ordinary in the moment, and that there may be other times, other places, where such encounters occur unnoticed, hidden within the everyday, waiting for the right conditions to reveal themselves briefly before dissolving once more into the unseen