Gottfried and Sophie Kummer live freely and independently with their six boys in a modest cottage in the countryside. Although the cottage has neither electricity nor running water and must be heated with wood, the small wages of a construction worker are not enough to meet all their obligations. Especially since the former owner, Mayor Lüthi, still has a mortgage on the cottage, on which the Kummer family must pay interest. And this interest makes life difficult for the Kummer family. Then a stranger appears who would like to buy the cottage as a vacation home. But for the Kummers, it is their home! Mayor Lüthi, however, senses a big deal, promises the stranger the house, and at the same time gives the Kummer family a final payment deadline for the interest until the end of the month. So it is the six Kummer boys who take up the fight to save their cottage.