It was a warm, late spring evening when Lena, Kuba and Emil gathered on the boulevards under the Silver Bridge in Krakow. Wrapped in the soft light of lanterns, the old stones of the bridge seemed to whisper stories as old as the city itself. Lena, a biotechnology student, held in her hand a small, chipped medallion with strange inscriptions. She had found it during a walk in the Planty and since then she could not stop thinking about it. Kuba spent his evenings reading old urban legends in the university's digital archive and Emil, an artist, sensed an atmosphere around the bridge that he couldn't describe. That evening, their curiosity and desire for an urban adventure united them, as the rumour about the medallion spread throughout the dormitory. - Here it is! - exclaimed Lena, pointing to a spot under a pillar closer to the Vistula. The stone slab stood out from the rest like the touch of a mismatched jigsaw puzzle. They uncovered it together, and then a current of cool air shot out from under the board. The medallion in Lena's trembling hand trembled and glowed with a milky radiance. Underneath the board, a round recess appeared, fitting the medallion perfectly. Lena placed it inside, and the ground split silently. A light emerged from the shadows - soft, silvery, yet eye-catching like a touch of infinity. - What is it? - whispered Emil, swallowing his saliva. The light began to swirl, forming a shape resembling a door. From within the portal came quiet sounds like a melody neither of them knew: deep, resounding under the skin, but disturbingly beautiful. Cuba carefully brought his hand close to the swirling portal. The light enveloped his fingers and - to everyone's amazement - the boy disappeared in a flash, as if he had been sucked into the abyss of light. Lena and Emil looked at each other; their hearts were pounding like crazy. - 'We have to follow him,' Lena whispered, and grabbing Emil's hand, together they crossed the threshold of the swirling light. In an instant, the world around them fell apart and they felt as if they were falling through glittering tunnels. After a moment, they landed on top of a tall, shiny platform floating in the air. The entire space around them was criss-crossed by suspension bridges, on which walked figures with bodies woven from light and shadow. Gravity seemed to be non-existent here - the sky flowed beneath their feet and the clouds were arranged in geometric figures. In the distance they spotted Cuba, who was talking to a being that resembled both a human and a plant. The shimmering figure pointed at them and suddenly the whole platform began to tremble, as if something huge was awakening beneath it. Lena, Emil and Kuba looked at each other, seeing in their eyes the reflection of an unknown world whose boundaries they were yet to discover....