Cor and Jan are two Dutch students who work in a hospital. A smallpox epidemic has broken out, but the country's capital is occupied by the army. Nevertheless, someone has to go outside the city to get a serum. Cor and Jan steal an old car and make their way through the military lines. It's not easy, but they're smart guys.
Dik Trom hears that Oude Kee no longer has any money to buy food. Dik and his friends decide to help her and collect money for a small organ with which she can earn a living. They also give her some money, but it is stolen by Oude Kee's cousin. Dik wouldn't be Dik if he didn't catch the rascal after many exciting chases.
