The Disappearing Bell at Poplar Tree School

The Poplar School looked perfectly ordinary - old red brick, long corridors and the bell that always annoyed everyone before maths lessons. But something strange was happening that morning. The bell did not ring. Instead, a soft green flash flashed across the corridor, which only Lena, Igor and Maks saw. Lena had long suspected that she was different. Sometimes she understood what the dogs in the yard were thinking, and when she touched the leaves of the backyard maple tree, she felt as if the tree recognised her. Igor had incredible reflexes that were the envy of everyone at gym class - he could catch a ball before anyone had time to notice it. Maks, on the other hand, had a flair for technology: he could rock a radio, build a paper aeroplane that really flew, and recently his phone displayed notifications to him before they reached the other children. That day, all three of them skipped to their secret base under the stairs for recess to discuss the strange green flash. As soon as they entered the corner, Lena heard something eerie: a soft whisper, quiet as the breath of the wind. "Find what you can't see..." - repeated in her head. Igor tried to joke that it was probably just a new fire alarm, but when Maks took his phone out of his pocket, the screen went blank and then lit up with a strange blue light. The display showed a plan of the school with a flashing green dot just below the biology room. - Do you think someone stole the ringtone? - whispered Maks. - Or maybe it's something trying to help us? - replied Lena, looking at Igor. They all moved towards the biology room, trying not to draw attention to themselves. Suddenly, when they were already at the door, they heard quick footsteps behind them.... and then the door in front of them opened with a quiet creak. Should they go inside? What was waiting on the other side? And why were they the only ones who could see everything?