In the heart of the town, on the main square, an old, spreading maple tree grew. Its thick branches reached all the way to the roofs of the neighbouring houses, and its roots twisted around the ground in fanciful patterns. The children called the tree the Maple King and told each other all sorts of stories about it. This time, siblings were playing under the maple tree: twelve-year-old Lena and her brother Tymek, who was one year younger. Lena was always curious about the world and was never afraid of challenges. Tymek was fond of adventures, but most enjoyed them in the company of his sister. One April afternoon, when the park was filled with singing birds and a warm breeze, Lena noticed something unusual. A shallow hole in the ground had appeared between the roots of a maple tree, although it had not been there that morning. She knelt down to look into the darkness. - Tymek, come here! - she called out, trying to shovel away some dry earth. The boy ran up holding a stick in his hands pretending to be a sword. - What have you got there? - He asked, peering over his sister's shoulder. - Look! It looks like there's a hole under the tree. Maybe the foxes have dug a burrow? - wondered Lena, but she quickly spotted something shiny between the tangle of roots. When touched, the earth began to crumble like dry sand and the hole grew larger and larger. Suddenly, Lena saw a circular frame of metal under the roots, covered with strange markings. The tree trembled slightly and the air around them rippled. - 'Lena... it's probably more than a burrow,' whispered Tymek with his eyes wide open. Lena reached out and touched the metal frame. She immediately felt a slight tingling under her fingers. At the same moment, a light flashed between the roots. The smooth surface under the frame began to swirl, as if it were made of living silver. The siblings looked at each other. Neither of them said anything more, but they both knew they had to see what was hidden on the other side. Lena squeezed Tymek's hand and moved closer to the portal without hesitation. Around them, everything became quiet - even the birds stopped singing. The portal whirled faster and faster until suddenly a chill pierced the air. Lena and Tymek held their breath. At the same moment, the surface of the portal rippled and showed an image of an unknown place: they could see a huge meadow with purple grass and strange, glowing animals strolling under a tricoloured sky. - Ready? - Lena asked quietly. Tim just nodded, and his hand trembled slightly in his sister's palm. And then... the portal glowed even brighter, as if inviting them inside. Lena and Tymek looked at each other one last time, then slowly slid their hands into the swirling light....