Like many other couples, teacher Sina and doctor Carl have lost their love in everyday life. They have filed for divorce, and their last words together were exchanged a long time ago. But on Christmas Eve, the disappointed husband and the overwhelmed single mother meet again on a crowded train between Salzburg and Munich. Old wounds are reopened and the two are back in the middle of the most beautiful marital tiff. In the best screwball tradition, male logic and female perspective collide. When the train gets stuck in a snowstorm, the angry couple's nerves are on edge. In their anger, Sina and Carl not only forget themselves, but also their son Felix (10), who is traveling with them and is completely overwhelmed by their arguments. But the other engers also have their worries, and it is only when the situation in and around the train escalates that Sina and Carl come to their senses.