Nina always said that the city breathes differently at night. That evening - the last one before graduation - the lush greenery of the park on Długa Street seemed to dampen the lights of the street lamps, and the air thickened with anticipation. The four of them gathered by the abandoned fountain: Nina, Adam, Sara and Michael. As they returned from a class meeting, Adam - hungry for excitement as always - suggested they check out the old entrance to the canals, which was whispered about among the locals. "It's illegal, after all," chuckled Sara with a nervous smile, although she herself wasn't sure if this was an objection or more of a stoked emotion. Nina remained silent, feeling the tension growing under her skin. The city at night sharpened their fears and excitement. They discovered a cloaked trapdoor behind the scrub. With the dexterity of a cat, Adam levered it open with a rod. The smell of damp brick and dust wafted from inside, and the light from the torches danced on the walls like dishevelled shadows. They descended the wet stairs, trying to hide their nervousness. In the tunnel, the world lost focus. Whispered jokes quietened and the crunch of gravel underfoot seemed too loud. Michael, normally sceptical, suddenly stopped, feeling the cool air on the back of his neck. "Someone was here the other day... Look!" - he lifted a crumpled letter in a waterproof pouch from the ground. Sara read aloud, her voice trembling. There was a plea for help and a map leading deeper, to a place with a mysterious sign. They stood in silence, realising that they were not the only ones who had gone below the town that night. The air was thickening with unspoken questions and growing anxiety. Nina looked at Adam. "We decide now. Do we go on, or do we go back?" - she asked, and her voice echoed uneasily through the tunnel. And then, there was a quiet rustling from the darkness, as if something - or someone - was coming towards them....