Ola and her younger brother Franek were spending their holidays with their grandmother Zosia in the countryside. Grandma had the biggest garden in the whole street. There were fragrant raspberries, a bench under an old oak tree and lots of colourful butterflies. But the most extraordinary thing was the inside of grandma's house. One rainy afternoon, when a thunderstorm was rumbling loudly outside the window, Grandma suggested the children explore the attic together. Ola and Franek were delighted, because the attic was full of puzzling objects: old games, books, forgotten dolls and hats. In a corner, under a pile of boxes, Ola found an old clock with a pendulum. It was all decorated with gold stars, and its dial had strange stamps instead of numbers. When the children touched the clock's hands, they heard a quiet ticking, and suddenly the whole attic began to light up with blue light. Franek grabbed Ola's hand. - What's going on? - he called out frightened. Suddenly everything was swirling. A moment later the children stood in a completely different place. It was the same country road, but instead of cars a strange horse-drawn cart was driving along it. Grandma's house looked completely different, and there were children walking around in old-fashioned clothes. Ola and Franek exchanged puzzled glances. Could it be that they had travelled back in time? And would they find their way back to Grandma Zosia? Suddenly they heard laughter and quick footsteps of approaching children....