Bassie & Adriaan are in Denmark. There they will receive the package from the hands of a children's friend, but who is that? When Bassie sees a Viking ship during his search through Denmark, he thinks he is dreaming. But when he suddenly sees B100, he knows he is wide awake. After Denmark, Bassie & Adriaan go to Belgium. On their way there, they are having a great time. They are traveling in a hot air balloon. From the balloon, they look out over beautiful Belgian towns and villages. But they don't see that B100 is preparing an ambush under the balloon...