This Christmas everything is different at the Wagner family's home. As the family awakens to a loud crash and finds a large elk sitting awkwardly by the chimney in the house. Meet Mr. Moose. He had been preparing for a test flight with Santa Claus's team of reindeer and sleigh when it ended abruptly and he fell out of the sky through the family's roof. However, the children (Bertil and Kiki)'s excitement over the new domestic pet in the family is short lived, because not only has an amateur hunter Pannecke (Jürgen Tarrach) set his sights on the elk, but also Santa would like to have his elk back before the festive season starts.
Agathe von Trapp, the eldest daughter of a well-known musical family, overcomes many obstacles to pursue her musical career and move to the United States.