The workshop smelled of cat oil and centuries-old dust when I found the box beneath the rotting wooden floorboards, right where rainwater had formed a dark, hourglass-shaped stain. My name is Elias, I'm forty-three years old, and I've been repairing dead watches for two decades in this windowless basement on Flores Street, but I'd never felt the weight of such absolute stillness as emanated from that black mahogany box when I lifted it in my trembling hands. There was no lock, just a rusty brass clasp that yielded to the pressure of my thumb with a click that sounded like a joint dislocating, and inside, wrapped in threadbare velvet, lay a pocket watch whose face had no numbers, only concentric spirals that seemed to spin against the light even though there was no light in the room except for the yellowish bulb hanging from the ceiling. I opened it without thinking, like someone opening a door that should remain closed, and the hands moved backward with a violence that made my wrist vibrate while the workshop air grew thick like rancid honey, and suddenly the cut on my index finger that I had made that morning at breakfast disappeared, the blood receded like an ashamed tide, and I knew without needing proof that I had gone back three hours in time. I put the watch in my apron pocket, not like a treasure but like a death sentence, and went out into the street where the sun was exactly where it shouldn't be, higher, crueler, and people walked by unaware that I had already lived this afternoon once, that I had already seen that woman in blue stumble on the curb and the man at the newsstand lie to her about the price of the candy. The first time I used the clock, it was out of vanity, to avoid an argument with my sister about our father's inheritance that had ended in shouting the night before. I went back just twenty minutes and changed my words, said what she wanted to hear, and she smiled, and I felt a god-like ecstasy that lasted exactly until dawn when I woke up with white hair at my temples and fingernails yellow like those of an eighty-year-old smoker. Time charges interest, I told myself, but I didn't know the real exchange rate until the third time, when I went back a whole day to save my cat, Tuna, from being run over by the garbage truck. When I returned to the present, my left knee, healed since I was twenty after a bicycle accident, ached again with the sharp pain of that poorly healed fracture, and I saw wrinkles on my face that hadn't been there before, and I knew that the clock didn't steal time from the universe but from me, that every second recovered was a day of my life converted into currency. But I was already addicted, who wouldn't be, with the power to erase mistakes, to say yes instead of no, to kiss the one who had been lost, to not say what hurt, and I used the watch seven more times in that cursed week, going back minutes, hours, once three whole days to avoid the fire in the building next door that left us without electricity, and each time I paid with parts of my body that aged prematurely, with my eyesight that blurred, with my breath that ran out when climbing stairs that I used to climb two at a time. The tenth time was different; I didn't use it out of fear or regret, but out of scientific curiosity. I wanted to know what would happen if I turned the hands forward instead of backward, if I could see the future instead of changing the past. And when I did, I saw my own workshop, but empty, covered in cobwebs as thick as curtains, and my body on the floor, mummified, with the clock clutched between my skeletal fingers. The date on the wall calendar, which didn't yet exist, marked the year 2047, twenty-one years in the future. And I knew then that I wouldn't die of old age, but that the clock would consume me completely at some point not too far off. I tried to destroy it, of course, I hit it with the hammer I use for stubborn springs, I threw it into the river on a moonless night, I buried it in the cemetery under three meters of earth, but it always returned to my pocket at dawn, clean, spotless, ticking, waiting, and each time it disappeared and reappeared my hair became thinner, my back more hunched, my organs more tired. So he decided to use it one last time, not for me but for her, for Marta, the woman I loved for ten years and who died last winter in a car accident I could have prevented if I'd had the watch then, but didn't get until later. I went back six months, felt my body disintegrate and rebuild itself during the journey, lost years of my life in seconds of transition, and appeared on the day of her death, on the corner of Rivadavia Avenue where the bus would run her over at five in the afternoon. I saw her walking with her red umbrella, alive, breathing, and I ran toward her shouting her name, but my voice came out like the whisper of a decrepit old man. When she looked at me, she didn't recognize me. I saw terror in her eyes because I was a hunchbacked, bald stranger with hands like a stuffed bird. I tried to explain, to stop her, but she backed away in fear, and just then the bus turned the corner too fast, like the first time, like always, and I screamed and turned. The hands of the clock, desperate, wanted to go back just a minute to try again, but the mechanism resisted, it heated up, it burned my skin, and I understood that I had exhausted my time credit, that I had no time left of my own to exchange, and then the clock did something new, something it had never done before, it opened by itself and revealed a secret compartment where there was a piece of paper folded a thousand times, and I unfolded it with fingers that no longer felt and read my own handwriting, my calligraphy from fifty years ago or from tomorrow, which said: Don't try to save her, Elias, I already tried a thousand times before you, and failed a thousand times, and each time I wrote this note for the next us who would find the clock, because we are not the first Elias, nor will we be the last, we are an infinite chain of clockmakers who have lived this same week for centuries, condemned to repeat it until one of us breaks the cycle, until someone accepts letting Marta die, destroying the clock for real, or simply leaving it abandoned for another to find, but you know you can't do it, you know that You will try again, you will turn the hands once more even if it turns you to dust, because love is stronger than logic, and the clock knows it, it feeds on that, on our refusal to accept the irreversible, and now look me in the eyes, new Elias, look at me closely because I am your future and your past, and as the bus inevitably approached Marta who didn't recognize me, I felt the clock begin to devour me, not only the years but my very existence, how I faded into particles of gray light, and the last thing I saw before becoming nothing was my own skeletal hand holding the clock, the same hand I had seen in the future, closing the perfect circle, and then I understood that it had never been a magic clock but a cosmic trap for stubborn souls, that I was both the hunter and the prey, the beginning and the end, and that somewhere in time, in this very basement on Flores Street, a younger Elias had just lifted the mahogany case from the wet floor, feeling the same The shiver I felt, preparing to repeat the same mistakes, to pay the same debt, to write the same note that was now disintegrating between my ghostly fingers along with everything I was, and as total darkness swallowed me like a black hole made of stolen seconds, I heard the click of the clasp opening, the same sound of a dislocated joint, and I knew that it was all starting again, that it always started again, that it would never stop starting, and that you, who are reading this now, who are curious about this object you found in your great-uncle's basement or in your grandfather's safe or simply on the street with a free sign, are already trapped, because reading these words is the first step, the invisible hook, and soon you will feel the need to open the lid, to turn the hands back just a minute, just to see what happens, just to correct that small mistake of this morning, and then you will be me, and I will be you, and together we will be the eternal echo of a time that does not forgive, so keep this message safe, Write it again when you reach the end, when you are dust and light, because the next us will need to know the truth even if it is too late, will need to understand that the clock is not an instrument but a predator that has been devouring watchmakers obsessed with fixing the irreparable for centuries, and now that you know, now that you know the price, tell me, are you going to leave it there untouched or are you going to open it? Be honest, we both know the answer, we always know it, we always open, we always turn, we always pay, because hope is the clock's last trap, and you just fell into it like we all did, like you will, like we eternally fall into this dead-end basement where time doesn't pass but accumulates like ash, waiting, always waiting, for someone else to sit down at the workbench and say those damned words: just one minute, just one more minute, I want to see what happens if.