Suddenly, two horses appear in Uncle Albert's meadow. Tim and Anna are puzzled. What does Uncle Albert have to do with horses? A lot, he thinks. Because in the past, when he was still a miner, he even had a horse as a work colleague underground. Tim and Anna can hardly imagine working in a coal mine. But Uncle Albert explains it to them. He shows them what his mine looks like above ground, tells them how he was buried deep in the earth, and in the end, he even finds a way to take the children underground. The three of them have great adventures, as Anna and Tim never imagined the world of mining could be so exciting.