Hania stood on the edge of the open manhole, peering deep into the black well leading underground. The night wind tugged at her jacket, as if trying to dissuade her from this decision, but Hania was resolute. Immediately behind her, Christopher appeared, holding a torch in his hand and smiling nervously. - 'Are you sure this is a good idea? - He asked, but didn't try to stop her. They were in the ruins of an old factory whose history had always intrigued the local youth - stories of mysterious experiments, strange sounds and even disappearances. Now that the area had been closed off and no one dared enter, their curiosity was greater than their fear. Hania lowered herself carefully down the ladder and Christopher followed her. The narrow tunnel was filled with dust and the smell of dampness. All that could be heard was their breathing and the rustling of their shoes on the metal rungs. After a few minutes, they descended to a small platform. In front of them stretched a huge corridor, the walls of which shone as if they were covered with glass. - Look! - whispered Hania, pointing to a strange light cutting through the tunnel. Krzysiek walked past her and touched the wall. After a few seconds, the glass surface began to pulsate with colours, and another door appeared in front of them. When they opened them, they were completely unprepared for what they would see. They found themselves in a huge underground city. The glass buildings shone with their own light, and the wide avenues were completely empty. Above their heads, colourful moving images shimmered, as if the whole city operated according to different rules of physics. - Is it ... real? - Krzysiek grabbed Hania's hand, unable to take his eyes off the swirling shapes. Suddenly there was a quiet rustling sound. A silhouette emerged from one of the alleys, where the lights were particularly intense. Footsteps echoed off the glass, and the figure's shadow lengthened unnaturally, gliding towards them. Hania felt her heart beating faster - they stood still, uncertain whether this strange creature was friendly or the opposite. The shadow stopped a few steps away from them. Tension hung in the air, and the glass city around them seemed to freeze in anticipation of its next move. Hania and Krzysiek exchanged glances - they knew they had just crossed the border of ordinary reality. What would happen next...