Lena has always known that the old quarters of the city hide more than peeling plaster and broken windows. As a child, she would go there to see if by chance she would stumble across something that shouldn't exist. Now, at seventeen and with a head full of more real worries, she ventured into the area less often. But on this particular Saturday, she had had enough of everything: the arguments at home, the upcoming midterms and the feeling that everyday life was increasingly overwhelming her. Slawek was her opposite. Calm, composed, always with a smile, as if the world had no power over him. He was the one who persuaded her to go into the old tenement on the corner of Olchowa and Brzozowa. It was one of those childhood places that Lena never dared to look into. They entered through a sunken door that no one had yet managed to board up. The darkness inside was almost palpable, as if the walls had absorbed all light. Slawek shone the torch on his phone - its light scattered the dust floating in the air and cast twitching shadows on the walls. "Imagine, this is where whole families used to live," he muttered, looking at the rusted door hardware. "Do you think there's anything left of them?" Lena slid her hand along the railing and looked under her feet. A coloured fragment of tile flashed under a layer of rubble. They descended into the basement. There, an old corridor led into the depths, where the concrete walls were becoming strangely damp and cool. At one point Lena felt as if the air began to tremble. They stopped in front of an iron gate. Between the crumbling bricks were quite clearly outlined mysterious signs they had never seen before - they resembled a mixture of geometric patterns and something that resembled musical notation. "It looks like some kind of code," Slawek whispered. He moved the torch closer. A doorway emerged from the shadows - an old doorway, covered in shards of glass, on which the light shattered in a disconcerting way. "Pull?" asked Lena, feeling her pulse quicken. Slawek nodded. Lena grabbed the cold door handle - with difficulty, as something seemed to be trying to hold her hand. The door gave way with a heavy sigh. Behind them stretched a corridor, completely different from the rest of the basement; the walls shone as if they were made of metal, and the air vibrated with a strange energy. They took a step inside. Time seemed to slow down. Every sound echoed. Outlines of figures began to emerge from the walls - translucent, fluid, seemingly inert. Suddenly, a quiet creak sounded behind their backs. The door closed of its own accord and the torchlight went out. Lena and Slawek found themselves in a place they could not imagine and which seemed to be waiting only for them.