Lena was fourteen years old and hated waiting for late trains. That afternoon she was roaming the corridors of the very old railway station in Toruń. Her grandfather ran a small clockmaker's shop here under a huge, cracked clock. He was just closing it when Lena rummaged a strange pocket watch out of a box. The metal was icy, the hands were solid and a warning was engraved on the lid. "Do not open unless you know the date," proclaimed the cursive engraving on the brass. "How did it get here?" she asked in a whisper, tucking the watch deeper into the sleeve of her jacket. Grandpa went pale as if he had just walked through a draught from another world. "It's a memento of someone who once didn't come back," he replied, extinguishing the lamp over the table. "If you hear three bangs, don't spin the crown, just run away immediately." Before Lena could ask further, the megaphone blared and called a platform that did not exist. Platform twelve, special train, please be careful, repeated twice without date. No one seemed to hear it except her, which was the strangest thing. The watch twitched and pulsed with a chill, as if a heart had been awakened within it. Behind the postcard kiosk, she found a taped door with a symbol of crossed hands. The same pair of clues was etched on the lid of her find. The rustling of the tape quieted as Lena thrust her shoulder and stepped inside. Before her stretched the platform, clean and unmarked, with a departure board full of dates. 1918, 2055, the third of May, the first of September, no hours, just years and days. On a bench sat a boy in a conductor's sweatshirt, younger than the timetable. "You're late for your own train, Leno," he said, as if they had known each other for a long time. "How do you know my name?" she choked out, clutching her watch so that the metal wailed. "From the fact that you've been here before," he replied, pointing to the blackboard where today's day was flickering. The speakers hummed, the ground beneath the plates trembled, and a light came on in the tunnel. The clock began ticking backwards, slowly, insistently, along with the increasing swish of oncoming wheels. The date she had been avoiding all her holidays flashed on the front panel of the locomotive. The doors slid open with a hiss and a gloved hand slid out of the carriage. A crumpled ticket with her name and today's date printed on it fell onto the platform. "Lena Bednarska?" called out the megaphone, and the boy nodded, indicating the centre of the open door. "Last call for a course without a date," he said, when something familiar flashed inside. And then someone in the carriage told her a secret she hadn't told anyone.