It was summer, and Catherine, Kuba and Lena decided to spend their summer holidays on the border between the town and the forest, where an old, disused astronomical observatory stood. The locals claimed that the building had been abandoned for years and strange sounds could be heard coming from it at night. For the three friends, it was the perfect opportunity to feel like characters from their favourite science fiction films. One day, armed with torches, a healthy snack and drawing notebooks, they cautiously entered the building through a tilted window. The interior smelled of dust and old paper. In the middle of the largest room stood a dusty computer, larger than any they had seen at school. Next to the monitor lay a notebook in which someone had written several pages of strange characters in cipher. Suddenly, the computer switched on by itself. The screen flicked on and a morse-like crackling sound came from the speakers. "Do you hear that? Those are some kind of signals!" - whispered Lena excitedly. Catherine began to transcribe the mysterious code from her notepad, while Kuba tried to decipher what the strings of zeros and ones flashing on the screen meant. Suddenly, the computer emitted a loud warning sound and a message appeared on the screen: "WARNING: TRANSFER COMING". Blue lights flashed from the ceiling and the floor began to tremble slightly. The children looked at each other, their hearts beating like crazy. They didn't yet know whether they had just discovered the beginning of a great cosmic adventure or....