Simon stared at the overgrown ditch near the border of the old forest. He sat on a log next to Karolina, who glanced uncertainly into the thickening mist. Behind them, closer to the campfire, Alan was walking restlessly - always ready for an adventure, today exceptionally silent. It was already late at night. There were sounds of the town from far away, but here, at the edge of the dark stand of trees, everything seemed different, distant, quieter. During an earlier game of treasure hunt they had come across an old stone, with a barely legible inscription. Simon read aloud: "Those who wish to discover must enter without fear." They soon discovered that if they touched the moss on the stone, a narrow crack in the ground opened up, revealing a staircase leading under the roots of old oak trees. They hesitated for only a moment - after all, they had promised themselves that no riddle would go unsolved. With torches in their hands, they slowly descended deeper and deeper. The walls of the passage were wet, the cold mixed with the strange smell of earth and leaves. Footsteps echoed. Suddenly Carolina stopped abruptly, listening to the silence. - Can you hear it? - she whispered. From deep in the darkness came a deafening, steady sound, as if someone was dragging something heavy along the ground. Alan raised his torch and pointed the light ahead. To their surprise, they saw a hazy silhouette in front of them, emerging from the darkness. Suddenly, the entire ground beneath their feet trembled slightly, and a drawn-out, throaty whisper that was impossible to understand came from the distance. At the same instant, the light of the torch began to flash and a strange noise rang through the air. The three friends held their breath. A corridor like they had never seen before opened up in front of them. To the left, on the wall, strange signs flashed. - What now? - whispered Simon, looking uncertainly at the others. Karolina and Alan looked at each other, trying to decide. The deafening sound echoed again, this time much closer....