The old railway station in Green Valley died a few years ago. The tracks were overgrown with tall grasses and the echo of the train whistle had long since ceased to echo through the grey hall. There was something incredibly enticing about the place - something that attracted Amelia, Tymon and Daria even more than the legends circulating around it. As high school students with a flair for breaking bans and a love of adventure, they couldn't resist when one afternoon they found a metal key in a crevice in the wall, right at the entrance to the platform. "Are you sure there isn't something here?" - Daria asked quietly, raising her torch. She swallowed her saliva and looked at Amelia, who was holding the key. Around them, the air seemed to thicken with anxiety. "If we didn't check, we'd never know," Tymon replied, with all his confident smile, though his voice trembled slightly as well. Night fell quickly, and the patterns of light in the trusses of the roof danced a bizarre dance as they moved forward. Outside the windows of the hall, the mist was quietly falling. The old clocks, although indicating different times, seemed to be watching them from above. When they finally found the door to the previously inaccessible engine room, Amelia tried to turn the key in the rust-covered lock. Something clicked and the door opened with a groan. Inside, it smelled of dust and grease, the shelves bending under the weight of dusty binders, assorted tools and... something else. Behind the desk was a book of notes - no author was visible, and the first page was full of strings of numbers, graphs and strange symbols. Tymon came closer and ran his finger over one of the pages. At the same moment, there was a sound in the distance, as if something metal had fallen to the floor. The torches trembled in his hands and a sharp whisper pierced the air: "They're here..." The friends looked at each other in horror. Were they no longer alone? What was really going on in the old train station? Suddenly, Amelia's torchlight began to flicker, and a flickering circle of lights emerged from behind the shelves....