Julka has always been fascinated by old buildings, collected postcards from the past and dreamt of a great adventure. One summer afternoon, when the sun was warming the stones on Plac Defilad, she was standing with Marek on the platform of Warsaw's Central Station, waiting for a late train to Gdańsk. In the crowd of people, between the glittering shop windows and the smell of coffee wafting through the air, they noticed something unusual. On the left, just behind the newsagent, was a massive, heavy door, completely out of keeping with the rest of the modern station. They had carved decorations in the form of strange clocks and numerals. Nobody seemed to notice them apart from them. - Do you see that? - Marek poked Julia with his elbow. - This door... They certainly weren't here yesterday. Unable to resist curiosity, they walked closer. On the handle hung a small medallion with an engraved date: 1939. Julka gently touched the medallion, and then the door creaked and swung open on its own, revealing a dark corridor. Despite their apprehension, they both stepped inside - there was silence all around, broken only by the ticking of some old clock. Outside the door, it was very different from the station. The stone floor led deep into the corridor, and portraits of unknown people hung on the walls. On each side stretched a massive wooden door, and above each was a different date: 1667, 2022, 1918. They realised they were in a place that allowed them to travel back to selected years from history. Excited, they almost couldn't believe what they were seeing. - 'Let's try this door with the date 1939,' Julka suggested, in a whisper, as if she was afraid of waking the ghosts of the past sleeping somewhere in the corridor. Marek put his hand on the door handle. A moment later, flashing images began to come through the gap in the door: trams, uniforms, the bustle in the street, children's laughter. As soon as they pushed open the door, however, they heard someone's footsteps just behind them. Someone was in the corridor, and they stood between the present and the past. Before they had time to turn around, they felt a gentle tug, as if the whole world had started to spin around them. The door slammed shut and they were engulfed by a blinding light. They had no idea where the unknown force had taken them, or who was the mysterious companion of their journey....