Gabrysia jumped up and down, unable to contain her excitement. Finally, colourful posters appeared over their town with the words: "Circus Horizon invites you! The biggest show this spring!" She and her younger brother Simon had been dreaming of seeing jugglers, clowns and trained animals for weeks. The circus stood in a huge clearing behind the school. The tall tent shone with red and gold fabric, and the smell of candyfloss and popcorn wafted around. Gabrysia squeezed the ticket in her hand. - Do you think we'll see a levitating illusionist? - she asked Simon, who was looking around for the fireman his friends had told him about. A fanfare sounded from the loudspeakers and the audience went inside. Inside the tent, the lights flashed and the music played faster and faster. Kiko, a clown on a unicycle, flung coloured balls like rain across the arena. Soon the stage was taken over by Mr Ambrose, a magician with a beard to the ground who could make pigeons turn into clouds of confetti. But the children were most impressed by Maximus, a young, mysterious artist who invited volunteers into the Cabinet of Mirrors: a huge, silvery tent hidden behind the stage. - Only the bravest go inside! - Maximus announced. Gabrysia - although her heart was beating faster - decided to raise her hand. Simon joined her, squeezing her shirt sleeve. Together they went inside the tent, where the walls reflected their reflections endlessly. There were other child volunteers there too. Maximus laced the entrance and said: - In a moment the extraordinary show will begin. Before the lights went out, Gabrysia managed to notice something strange - one of the mirrors did not reflect people at all ... but a blurred silhouette that moved with its own rhythm. Suddenly, the lights in the tent went out completely. Silence reigned, only the echo of the children's breathing echoed off the walls. Then, from the depths of the tent, there came a rustling sound and someone whispering: - This is the moment. - A moment later, all the floodlights went out and Maximus... disappeared without a trace! Gabrysia started nervously looking for her brother in the darkness. Simon grabbed her hand. A soft clatter sounded, as if someone was moving across the floor. And then the mirrored walls began to slowly rotate around them, forming a tunnel leading deep into the unknown part of the circus. The children, clasping their hands tightly together, decided to go inside the rotating tunnel. Eventually, they had to find out what really happened to Maximus - and whether the Cabinet of Mirrors really hid something unusual....