Erik always thought his grandfather had the most interesting things in the world. In his dusty study, full of books and strange devices, every shelf hid something unusual. One Saturday afternoon, Erik and his friend Ola came to visit their grandfather, hoping he would show them something new. Grandpa, with a mysterious smile, took out a small gold pocket watch from a drawer. "This is no ordinary watch," he said, handing it to Eric. "You can open it, but only if you promise to be careful." As soon as Erik clicked the lock, the watch opened with a quiet clink. The hands began to spin wildly, and a swirling glow appeared all around. Ola grabbed Erik's hand, and before they had time to look up, Grandpa's room was gone. Instead, they stood in the middle of a cobbled street where carriages glided by and people wore costumes as if from old stories. Above their heads hung a sign: "Warsaw, 1880". Ola looked around puzzled, and Erik squeezed his watch tighter. "We have to go back!" he whispered. But as he tried to retrace the movement of the hands, the watch sizzled and froze. At the same moment, a boy in a baseball cap moved towards them, carrying something that resembled a telegram. "You two... you're not from around here, are you?" he asked, looking at them suspiciously. "Follow me. If you want to get home, you need to do something very important - and before the clock strikes midnight." Before Erik and Ola had time to react, the boy took off down the narrow alley. Caught in the middle of an adventure, they looked at each other terrified and excited, having no idea what awaited them around the corner....