When lessons were over, Karol, Lena and Igor stayed a while longer at school. It was quiet, the corridors deserted and the echo of footsteps echoed off the high walls. Their old school spanned two floors, one wing of which had been locked up for years. The teachers said it was because of the damp, but no one had ever looked there. - Do you think there's really anything interesting in there? - whispered Lena, glancing at the closed door with the "Do not enter" sign. Charles only smiled and lifted up the key he had found a few days ago. - Let's check,' he whispered. The door squeaked draughty, though the lock itself gave way all too easily. Inside, it smelled of dust and old paper. The ceiling was higher than in other parts of the school, and light streamed in through the coloured glass, giving the interior an eerie hue. At the end of the corridor, double doors awaited them, as age-old as everything around them. - Have you heard of these walls? - Igor looked at the others. - Apparently time passes differently in this part of the school. - 'Stop it, you're scaring and you're scared yourself,' Lena bounced the ball, but her voice trembled slightly. The double doors gave way under the weight of their arms. Inside, twilight reigned. In the middle of the great hall stood something neither of them had expected: a rectangular frame, laced with copper wire, filled with glittering light. As they came closer, the light shimmered. The image inside the frame changed - first they saw their reflections, but then, instead of the schoolroom behind them, a vast landscape appeared: a forest of silvery leaves, and above it a pink, swirling sky. - This... some kind of screen, I think? - Igor asked, trying to find a rational explanation. Lena reached her hand into the frame. Her fingers disappeared inside the light, as if she had dipped them into a sticky sheet of water. - Try it! - She said, and something between fear and delight flashed in her eyes. Charles swallowed his saliva and was the first to slide his whole hand across the shiny surface. On the other side he felt a gentle warmth and heard a distant singing, as if from the very centre of a dream. Suddenly something gripped his hand firmly from that side. Lena and Igor froze in place, watching as Karol was pulled into the light. The floor beneath their feet trembled slightly, and the light in the portal took on an even more intense colour. For a moment, it was unclear what would happen next. Lena held her breath, looking at Igor, while he stared at the shining frame. The decision was made - they had to act. What would they find on the other side and would they come out the same as they had entered?