Franek really enjoyed walking in the park near his house. One sunny morning, while he was picking chestnuts, he noticed something shiny under an old oak tree. He walked closer and was stunned. On the ground was a small stone that shimmered with all the colours of the rainbow. Franek carefully picked up the stone. At that moment, he felt something strange - his heart began to beat faster and his stomach became ticklish. "But I feel strange!" - he thought. He looked around, but there was no one nearby. The stone seemed to whisper quietly: "Discover my secret...". Frank felt a slight fear, but also a great curiosity. Was the stone really talking? Or was it all just a figment of his imagination? The boy wondered what he should do. He clenched the stone in his hand, and then his hand became warm and he felt a sense of courage within himself. Suddenly he heard the rustling of leaves behind him. He turned around and saw a large, green bush starting to move....