Uwe wants to rescue the dog Bootsmann, who is drifting away on an ice floe, with a small boat. But actually, Uwe is still far too young for such a task. It is winter. Uwe, Katrinchen, and Jochen have taken Bootsmann, the dog of tugboat captain Bräsing, out to play. It is very cold. Ice plates have formed along the shore. Jochen and Bootsmann are frolicking around until one of the plates breaks. Jochen manages to jump to safety, but when Bootsmann tries to do the same, the floe has already drifted too far away. Jochen sneaks off. Katrinchen is supposed to get help but does not return. Left all alone, Uwe finds a small boat and rows after the drifting Bootsmann.