Ever since Kasia's family moved to a villa on the outskirts of the city that is more than a hundred years old, there has been no shortage of secrets in the girl's life. That evening, as the wind rustled among the boughs of the old oak trees, her friend Michael once again came to visit. They were both nineteen years old, studying computer science and loved figuring out the mysteries of the past. They were due to return to university soon, but the old boxes in the basement kept Kasia guessing. After dinner, they walked down the stairs, creaking under each step. There was a smell of dust and damp in the cellar. By the wall they found an iron box with an engraved inscription in Latin: "Tempus non revertitur". Kasia took out her smartphone and started looking for a translation. "Time does not return," she read quietly. Michael, fascinated by the intricacies of the old lock, dared to lift the lid. From inside the box, they pulled out a rounded metal object that resembled a clock, but had many more hands and strange buttons. Numbers flashed on the screen: 2032, 1997, 1492... Kasia, unable to stop herself, touched the brightest button. In the same instant, everything around them blurred as if it were a film unfolding. They felt a tug, as if someone had pulled them by the shoulders. Suddenly the smell of dust disappeared and the bustle of the city rang out around them. But this was not the city they knew. The streets were full of cars whose make they had never seen, small drones hovered overhead and billboards pulsed with colourful holograms. Kasia grabbed Michal's hand. "Something has gone wrong," she said in a trembling voice. Michal looked on in disbelief, clutching the device in his hand, which was still humming quietly. Suddenly, in the midst of the crowd, they spotted themselves. A dozen years older, walking towards them. At that moment, a warning sounded from a loudspeaker hidden in the lantern: "Attention, a space-time disturbance has been detected. Please report immediately to the time control point." What should two teenagers do when they have just met future selves in a world they do not recognise?