Night fell quickly, and the June wind carried with it the whisper of leaves and the laughter of a group of friends moving away. Lena, Marcin and David were left alone under the old bridge, as usual at this time. The bridge, no longer in use for a decade, stood at the edge of the forest. The planks still clung to the half-torn beams, and underneath them flowed an overgrown stream - the perfect place for teenagers to meet, whose heads were bursting with ideas far crazier than parental prohibitions allowed. That evening, Lena had a premonition that something unusual was about to happen. Earlier, as she was descending the steps of the bridge, she had noticed a mark carved on one of the beams - a loop inscribed in a triangle, which had definitely not been there before. Martin laughed that it was the work of young children in the area, but Lena was not convinced. David tried to brighten things up with his phone, but the battery died at the exact moment the light fell on the sign. "Do you see these footprints?" Lena pointed to the mud by the platform. Small, animal-like prints led to the middle of the bridge, where the footbridge creaked menacingly under someone's heavy footsteps. No one was crossing, however. The boys looked at each other. When they heard a quiet clatter coming from under the bridge, they fell silent. Suddenly, something clicked in the bushes, and then the silence fell even deeper. Lena swallowed her saliva. Martin leaned over the railing, trying to see anything in the darkness. "There's something there," whispered David. His voice trembled, though he tried to sound brave. Lena looked around nervously. In the darkness under the bridge, a shadow larger than any animal they had known flashed by. They froze as the mysterious figure slowly floated upwards, and tiny golden lights began to ooze from the wooden beams.... Suddenly, there was a long whistling sound from the forest, the lights went out and something heavy shook the bridge. The heroes looked at each other in horror, unsure whether what they were seeing was a dream or a reality.