Long after dark, when most of the inhabitants of the town of Osetnica were already asleep, a colourful tent stretched at the edge of a clearing. Its walls shimmered with the light of lanterns, and the soft melodies of flutes could be heard amidst the quiet breaths of the wind. The Freak Circus visited the town only once a year and was more famous than any story in the old book. It was under this tent that something was about to begin that even the most vivid imagination could not have imagined. On this particular night, four people were waiting at the entrance to the tent. The eldest, Elka, was 12 years old and had always dreamed of becoming an acrobat. Her younger brother, Philip, dreamed of training wild animals, although he was most afraid of his own cat. With them were Simon, always star gazing, and Zosia, who never parted with her notebook. Neither of them had ever been allowed into a late-night rehearsal, but today the circus master's search for new talent invited them to help. "Remember," Mr Zelman, the master of ceremonies, said quietly, smoothing his shiny frock coat, "the circus at night is a completely different world. Anything can happen here." The tent inside resembled a huge cave of light and shadows. The animals were still napping in their pens and the clowns were practising juggling glowing balls that left strings of lights behind them like comets. Nets dangled from the ceiling where acrobats practised, and trails of glitter and coloured feathers glittered on the floor. "You guys come with me," an elegant acrobat in a silver mask said to Elka. "I need someone to help me check the safety of the ropes. It's very important." Philip was given an equally responsible role: feeding the miniature elephants nutty biscuits. Simon was to help operate the lights, and Zosia could look backstage and write down whatever she wanted. Each of them felt special. As Elka climbed the ladder, her legs trembled with excitement. A thin rope hung just above her, but in the glow of the lamps it seemed like a way into another world. Philip laughingly handed more biscuits to the elephant, who could almost dance the polka. Simon looked at the spotlights, from which colourful rays were emanating, and Zosia watched a magician rehearse, who disappeared before his assistant's eyes - he literally vanished into thin air! Suddenly there was a strange sound, as if someone had rolled huge maracas on the ground, and then a light flashed, blinding everything for a moment. A golden key fell from the ceiling, shining like a freshly polished medal. It stopped right next to Elka's foot. Everyone looked at each other in amazement. Where did the key come from? What could it possibly fit into? Before they had time to say anything, there was another, even more puzzling sound somewhere in the depths of the tent, and the darkness began to thicken right at the entrance to the mysterious, hidden passage behind the curtain. Everyone felt that something was about to happen that would change their view of the circus forever....