Plot synopsis: Documentary reports on the annual icing of the Oder in the 160-kilometer border area between the GDR and the People's Republic of Poland. Icebreakers from both countries with experienced skippers join forces to make the international waterway between Frankfurt and Szczecin navigable again. Everyone works hard as a team and even a broken-down ship cannot stop them from achieving their goal. A look back at the winter of 1947 with its flooding shows what the freezing of the river and the subsequent thaw can do if the ice floes are not drained into the Baltic Sea via Lake Dammsch in good time. The skippers from both countries have known each other for years and trust each other; the camaraderie that has developed on the Oder unites the people, they control the river in winter for the common benefit of all.