Ever since they were children, Milenka and Igor had dreamt of travelling into space. In their town, at the edge of an old park, stood an abandoned astronomical observatory. No one looked at the stars there anymore, but one night a round, dusty window shone with a strange blue light. Curiosity was stronger than fear. Milenka, with a torch in her hand, led Igor through the creaking door. Inside, they found a large telescope and lots of sky maps, but what caught their attention was the glowing console against the wall. The screen pulsed with a throbbing light and the numbers began to arrange themselves in a mysterious pattern. "Maybe it's a code for..." - began Igor, but Milenka was already touching the biggest button. At that moment, the floor under their feet began to rotate. The light was almost blinding. A moment later they were standing in the middle of some amazing place: a long, winding corridor with walls flashing with all the colours of the rainbow. Images appeared on the walls: planets, strange creatures, puzzling signs. As they moved ahead, they heard a strange voice echoing: "To return, you must solve the riddle of the Universe. You have only one approach..." Three doors opened in front of them. Each led to a different part of the labyrinth, and from behind each they could hear something different: the sound of the wind, the laughter of unknown creatures and the gentle clanging of bells. Milenka looked at Igor a little frightened. "Which door shall we choose?" - she asked. Igor was already about to answer when all the lights suddenly went out and something that looked like a shadow moved right past them....