Cuba and Zosia are siblings who really enjoyed playing together. One rainy afternoon, when it was too wet to play in the backyard, they decided to build a fort under their big, colourful carpet in their room. They stacked cushions, built towers of blocks and giggled with joy. Suddenly, Cuba noticed that one corner of the carpet was floating as if by itself, moved by a gentle, warm wind. Zosia looked at her brother surprised. - 'I think it's just a draught,' she whispered, but her eyes lit up with curiosity. Cuba gently lifted the carpet and saw something he had never seen before. On the floor was a small blue door that looked like it had always been there. It had a gold handle in the shape of a star. - Oh my! - exclaimed Zosia. - Where did this door come from? They both knelt down next to it and put their ear to the door. They heard quiet laughter, as if someone was playing behind the door. Cuba grabbed the handle and the door opened with a quiet creak. Beyond the threshold there was no floor, just a shiny staircase leading down to a place full of coloured lights. - Let's go down there! - whispered Kuba, holding Zosia's hand tightly. Together they began to carefully descend the stairs. The light around them shimmered and the walls were decorated with painted turtles in bowler hats, singing cats and dancing butterflies. With each step, the sounds became clearer - someone was playing a harp, someone else was singing a joyful song. When they reached the bottom, a huge clearing full of flowers opened up in front of them, with animals dressed in funny hats running among them. In the middle of the clearing stood a large golden clock, where the hands danced around the dial. Kuba and Zosia stood for a moment with their eyes wide open. Suddenly, a rabbit in a waistcoat ran out from behind a large flower bush and called out: - Hey, you! New visitors! Quick, because the surprise parade is about to start! The siblings looked at each other with delight and ran after the rabbit, not yet knowing what awaited them in this unusual clearing....