Lena had always known that the Emerald Forest was unlike any other. Ever since she was a little girl, she had heard the whispers of the trees telling her quiet stories, and the winds, instead of simply humming, humming melodious songs. This summer, however, the forest seemed even more mysterious than usual. One afternoon, as the sun was painting golden patches among the dense foliage, Lena came across something she had never seen before: a giant oak tree whose trunk was covered with glittering runes, and in its very centre was a door. It was low, carved as if for someone much smaller than a human, but covered in a green glow and decorated with silver leaves. Before Lena had time to think, she felt a gentle touch on her shoulder. She turned around and saw a boy about her age, whom she had never seen around before. He had red hair sticking up in every direction and large, curious eyes glinting in the light. - 'I am Kaj,' he said, 'and I know what lies behind this door. But if you want to find out, you'll have to trust me. Lena felt a thrill of excitement. She had always dreamed of adventure, and Kajel's presence only gave her courage. Together they pressed their hands to the door, which suddenly shone with a stronger light. They heard a quiet click, and the oak tree opened a passage to another world for them. Beyond the door, there was no longer the usual forest - there was a path of blue stones leading through shimmering purple scrubland. In the distance they could hear laughter and whispers, as if someone or something was watching them. Kaj looked at Lena and smiled mysteriously. - The key to return lies at the end of this path. But only those who solve the riddle of the forest spirit will find the way out. Are you ready? She did not have time to answer, because suddenly something rustled in the bushes. From the depths of the forest path emerged a figure shrouded in a cloak woven from leaves, its eyes shining like two lanterns. In her hands she held an old leather book whose pages moved of their own accord, as if they were being turned by invisible hands. Lena and Kaj held their breath as the mysterious figure spoke in a voice that resembled the rustling of a thousand leaves: - Whoever seeks the truth must answer my question.... And in the same instant, the light became more intense and everything around them began to swirl....