The wind carried with it the smell of candyfloss and popcorn. A poster with a colourful clown waved at the bus stop, and a large sign "Circus of Luminous Mirrors - today only!" shouted to passers-by. Igor, Lena, David and Zośka stared at it in disbelief. This was no ordinary circus. No one in the area had heard of it before, and they could find no information about it on the internet. - 'I told you,' Lena whispered, 'that something is not right here. After all, circuses don't just appear out of nowhere, and certainly not THAT kind of circus. Igor shrugged his shoulders and turned towards the shiny, navy blue and silver tent that stood in the middle of the old, abandoned football field. People were crowded around it and the atmosphere was thick with excitement and laughter. - Maybe they just have a good marketer? - laughed David, but even he felt a stab of anxiety as he looked at the huge revolving mirrors hanging above the entrance to the tent. They let a few children pass and crossed the threshold of the circus. Inside, instead of the usual rows of chairs, someone had arranged wooden benches, and in the centre of the ring were mirrors tied with sashes. There were flashing lights reflected in each of them, but something was strange about the reflections: sometimes the kids had different hairstyles in the mirrors, the adults were taller or shorter, and the shadows of someone passing them in reality appeared completely elsewhere. - Hey, look! - cried Zośka, pointing to a giant parrot that stood on the shoulder of a glittering artificer. But before anyone had time to look at it, lights flashed above the arena and jazz music rang out. The first performance - a fire juggling act - was exciting, but when the juggler disappeared in a puff of smoke and was replaced by a tall-haired acrobat, Lena clearly saw in one of the mirrors something running behind her. For a moment she thought it was the shadow of a boy in a bowler hat. She blinked - and everything disappeared. In subsequent shows, more and more unusual tricks appeared. The artist in the blue tailcoat began to levitate above the arena, her shadow in the mirror turning in a different direction to herself. When Igor looked to the side, he saw in the mirror how the entire audience was sitting with their backs turned to the arena, even though no one was actually moving. During the break, Lena pulled the boys and Zoska to the side. - This is... strange, isn't it? Igor nodded, but it was David who pulled out his phone: - 'Look, my screen blurs when I aim the camera at that mirror. It's like something is interfering with it. They returned to their seats, but this time each of them kept a close eye on the mirrors. When the final, biggest show of the evening - the 'Parade of Luminous Mirrors' - was announced, the lights dimmed, the music quietened and the whole arena sank into semi-darkness. Only the flashes reflected from the mirrors moved across the faces of the spectators as if they were living beings. And then there was a quiet, disturbing laughter that did not come from any of the performers, and the mirrors began to turn faster. Someone's pale hand slid out of one of them....