Lena was fourteen years old and lived above her Aunt Nina's pawnshop, in a tenement near the old railway station. After school she would sort out the shelves, putting away clocks, maps and strange compasses. One afternoon she came across a brass watch with a sky instead of a dial. The stars jumped as she brought it closer to the window overlooking the tracks. She called Kaj, who knew how to open the equipment without leaving any marks. Inside they found a tiny rotor, a thin magnetic needle and a note with rules. "Read it out loud and it will work". - muttered Kaj, winking. Lena smoothed the paper: Don't travel alone. Always come back through the same point. And one more thing: Never change your first memory," she read in a whisper. In the evening they slipped out onto the closed platform of the New Doba, quiet as a photograph. The clock on the wall ticked stubbornly at 19:12, and the board was empty. Only in chalk did someone write: Return every 243 hours, and drew an arrow to the tunnel. Lena set the date to 12 April 1912 and pressed the crown of her watch. The air thickened, smelling of smoke and frost, even though it was a warm May evening. First the wind turned, scattering newspapers that began to change the dates on the headlines. Kaj's phone caught the strange ERA-0 network, and the screen beeped like an old cathode ray tube. A mist slid out of the tunnel, with threads of light glinting in it, as if someone was ploughing through the night. Iron rustled on the tracks, each sound sounding simultaneously close and very far away. A conductor in a uniform from a century ago emerged from the mist, unfolded a ticket book and called out her name. - Lena Sarnowska? - He asked, as if checking the departure list, and the clock by the platform started again. Before she could answer, the watch slipped out of her hand and hovered in the air. Two dates appeared on the dial at once, 1912 and 2043, pulsing alternately. Kaj squeezed her arm and hissed: Don't say anything, look carefully first. Underfoot, the planks of the platform changed colour, as if they remembered other centuries and shoes. The conductor lifted his ticket tongs and the door of a carriage without a number shimmered in the mist. - 'It's time to board,' he said softly, and Lena suddenly smelled the familiar scent of icing. It was identical to the one in her first memory, which she had never told anyone. The clock by the platform struck once, a second, a third, and the world twitched a millimetre.