It was June, and the sky, though deep as a well, offered no respite from the stifling air. Three friends - Lena, Cuba and Paul - were walking through the tall grass to the ancient Oak Grove, hiding from the gaze of householders and nosy neighbours. In their village, it was said that the night of the summer solstice was the time when the boundary between worlds became as thin as a spider's thread, and the grove was inhabited by something better not to be awakened. But the young were drawn to the forbidden whisper of legend - of the hidden warmth of an underground fire that gave freedom to those who would find it. The night was sticky and the air full of the smell of damp undergrowth. They stopped by the largest of the oaks. Paul pulled out an old amber - an amulet left to him by his great-grandmother. Lena, the braver of the three, pushed the moss away from the mossy stone under which the sign of the ancients was said to be carved. "Do you hear that?" - whispered Cuba. In fact, in the distance something rustled in the bushes. Maybe it was a night hedgehog, or maybe something much bigger. Lena slid her hand under the stone, feeling the cold metal under her fingers. Then, suddenly, a faint greenish light flashed from the centre of the oak grove. The light shimmered unnaturally, moving across the trunks like water reflections. Paul squeezed the amulet so tightly that it hurt. Kuba, though trembling, could not take his eyes off the growing glow. Lena pulled a small key out from under the stone, carefully carved and covered with unusual markings. As soon as the key was in the air, the light thickened, taking the form of a shadowy silhouette under one of the oak trees. The friends stepped back, stunned and fascinated. The shadow moved, making a sound like the sound of wind among the rustling leaves, but there was no wind. Suddenly, the silhouette turned towards them - and the symbol engraved on the key glowed red. In that instant, everything in the grove became quiet. The shadow was getting closer and closer. Was it the spirit of the grove's guardian? A former god? Or perhaps someone even more unknown from the land of whispers? The three friends froze, not knowing whether they should flee or stay and ask what had been waiting for centuries under the old oaks....