Vanishing Corridor

The rain drummed against the windows of Primary School No. 7, and Lena sat on the window sill in the empty corridor. Usually at this time the school was noisy, but today all the students stayed in class. Lena, Jakub and Nikola were on after-school duty, so they were collecting lost things from the corridor. Suddenly the lights flickered and something strange caught their attention. Behind the lockers of number 14 appeared a door they had never seen before. The door glowed slightly green and moving shadows could be seen through the tiny window. Lena felt a shiver run through her whole body. - 'I think one of us is dreaming,' Nikola whispered, clutching the locker key in her hand. James, who always had the most courage, grabbed the handle. - 'Oi, I don't think we should...' - began Lena, but the door was already slowly opening. Beyond the threshold was not another room, but a completely different world: coloured crystals floated overhead and the air sparkled with light. To the eyes of the three friends appeared a strange inscription on the floor: "Choose your power. You have three minutes." Lena looked at her friends. Each of them reached out their hand towards a different crystal. As their fingers touched the surface, beams of green light shot out, surrounding them with lightning. Lena suddenly felt her entire figure fade away.... At the same moment, a disturbing rustling sound came from the corridor. The door behind them began to close, and the shadows from behind the window were fast approaching....