In the evening, as Kazimierz turned into a tangle of yellow lights, Lena sat in her grandfather's workshop cataloguing donations. On the oak countertop lay a box of chocolates with faded writing and a weight that betrayed the metal. Inside rested a brass pocket watch, scratched but still proud, with an engraved command: "Return before midnight of the past day". Next to it, someone had slipped in a century-old tram ticket and a fiche with a name Lena knew only from family stories. "Don't touch until I turn on the recorder," Natan said, leaning his bike helmet and bag of electronics in the doorway. He was working opposite, taking pictures of the stonework details, and then popped into it like a shelter. Lena nodded and lifted her watch by the cool chain. The hands trembled, even though she hadn't screwed the mechanism, and on the inner cover someone had honed a tiny scale, resembling a calendar without months, with mysterious 'Before' and 'After' markings. Put it to the microphone, we'll try to pick up the frequency, muttered Natan, twisting the knobs of the silver recorder. Lena pressed the crown. A silence so thick that the wall clock fell silent in half a tick struck the workshop. Outside the window, the neon lights went out, and instead of the sound of a tram, they heard the soft clatter of hooves and a distant bell that was no match for any modern tower. A narrow, clear signal appeared on the recorder, descending like a ladder down the band, in line with the movement of the retreating second dash. "It's no joke," Natan whispered, and his echo sounded like it came from another room. Lena brought her face closer to the dial and noticed that instead of the date, the word 'Thresholds' appeared. It pounded with rain, even though the sky had been dry just moments before, and lines began to light up in the cracks of the yellowed wall, as if someone was drawing a map with glowing chalk. The paths converged at the door to the courtyard, forming a thin arc that pulsed in the rhythm of her own heart. "If this is a mechanical joke, it's cruelly well done," she added, trying to feign calm. Natan took a step, but was pulled back, as if a rubber thread held him in the present. "Lena, don't go alone," he said softly, pointing to the pulsating edge. Lena gripped the watch more securely. A thin, almost invisible slider protruded from inside the lid, set between "Before" and "After". She moved it about a hair's breadth. The air stagnated and took on the smell of coal and heated copper; a draught ran out of the gate, carrying a tattered newspaper with a date she had not yet experienced. Just beyond the threshold, in the milky darkness, loomed the silhouette of a man in a decades-old coat, holding a photograph of a girl strangely similar to her. "Lena?" he called out, as if he had known her name forever. The watch clicked a second time, and the world in the workshop tilted, waiting to see which way he would choose.