The night was sticky with heat, and the town bustled with the bustle of a summer festival. Lidia, with her hair tied up in a messy bun, stood by the fence of the empty car park, next to Kacper, who was biting his nails nervously. Lanterns strung along the yellow and red tent created the impression that the air was pulsating with a mysterious light. The Aurora Circus had appeared in their town almost unannounced, and with every hour on the street, impatience grew. When they arrived, all the performers were already bustling around the arena. A clown in a black dinner jacket was combing his hair in front of a mirror, an acrobat was painting a glowing tattoo on his arm and a lion trainer was whispering something to the animals through the bars. The air smelled of candyfloss, dust and something Lidia couldn't name. "Maybe it's the smell of circus adventures?" - she thought. They joined the rest of the young helpers, hoping for a few hours of interesting work. The circus director, a corpulent man with a moustache twisted into two snakes, greeted them with a theatrical bow. He distributed the tasks, following each one with a careful glance from under his hat. On the very first evening, Lidia saw something she thought was unusual. During the rehearsal of the fire show, none of the performers spoke loudly, and their movements seemed to be synchronised to the music that was flying in their headphones, completely inaudible to outsiders. As the lights faded and the sounds of percussion came from the speakers, the artists would suddenly disappear into the shadows, only to reappear in the next area of the arena. Kacper was fascinated by the magician - a young boy who conjured butterflies in the air from colourful scarves during each show. But what was most intriguing was how, after the performance, the performer would put his hand over his heart and swear something in a whisper while looking towards the director. The following week, when the circus had already set up its tent for good, something happened that knocked them out of their rhythm. Lidia noticed that the flame-haired acrobat, Eve, was absent during one of the rehearsals. Her place had been taken by a new girl they had never seen before. She wore a mask painted with gold paint on her face and spoke just one word as they greeted her: "Silence". As time went on, Lidia and Kacper became more and more curious about the strange rules the performers had in place. They were not allowed to leave the circus grounds after dark, and before each performance they all lined up in a circle, exchanging a brief glance, as if they were linked by an invisible bond. One evening, Kacper overheard the director saying something to some of the performers about 'the last act' and 'the test of endurance'. That same day, Lidia found an old notebook with yellowed pages under the arena, full of sketches of unusual props and descriptions of tricks they had never seen in any show. At the end, with a trembling hand, someone had written: "If you decide to go behind the curtain, there is no going back." As the evening of the big show approached and the crowd began to stream into the tent, Lidia and Kacper exchanged a look full of excitement and anxiety. A decision stood before them - should they look behind the curtain and find out what the final act meant, or stay where they were safe? Their breaths grew shallower by the second, the lights of the arena slowly faded, and somewhere behind their backs there was a quiet clacking sound, as if someone was calling them inside....