Just outside Jullerup Færgeby, three children named Anton, Kaja, and Knud live with their parents in a lighthouse. Every day, the three children row into town to go on treasure hunts with their friends Vera and 44. Among other things, they find a secret cave, which they call "HH." Jullerup Færgeby is also home to old Captain Gus, who follows all the daily events in the town. He watches when the cutter comes home, when the oversized fish export truck drives through town, when the man in the crane is constantly unlucky and shouts "It's stuck", and when Anton repeatedly tears his trousers.