Lenka always knew that her older brother Tymek was a bit crazy. However, even she never imagined what would happen one Friday afternoon when they were sitting in their little house just outside the city, with their noses glued to their dad's old radio telescope. - 'Listen, something's humming strangely here,' said Tymek, turning the dial. Lenka frowned, because usually the humming meant that Tymek had accidentally adjusted something wrong again. But this time... - ...---...--...---... - sounded clearly between the crackles. Morse code! - Let's try to decipher it! - Lenka pulled a sheet of Morse code from a drawer. After a minute, the puzzling signs turned into a disturbing sentence: 'COME TO EUROPE. WE HAVE SOMETHING FOR YOU." - Europa? You mean Jupiter's moon? - Tymek turned pale. Lenka stood up abruptly. - 'It's definitely a joke. Or a disturbance. But... we can try to answer! For an hour they worked, soldering wires and turning the antenna to the east. Their transmitter did not resemble NASA equipment, but who cares? After all, Lem wrote that imagination is the best fuel. As dusk fell, Lenka wrote a reply: "WHO ARE YOU? WHY DO YOU WANT US ON EUROPE?" and pressed the red transmit button. The answer came faster than they expected. Instead of Morse code, the loudspeaker rang out with a sound reminiscent of whale song and.... the slam of a door opening. The lights went out and strange blue lights flashed around their house. Lenka and Tymek looked at each other with wide-open eyes. After a moment, a soft, metallic voice came from behind the window: - It's time to start the mission. Are you ready? And then there was a quiet noise, as if something - or someone - had just materialised in the garden....